pragma solidity =0.6.6;

interface IUniswapV2Factory {
    event PairCreated(address indexed token0, address indexed token1, address pair, uint);

    function feeTo() external view returns (address);
    function feeToSetter() external view returns (address);

    function getPair(address tokenA, address tokenB) external view returns (address pair);
    function allPairs(uint) external view returns (address pair);
    function allPairsLength() external view returns (uint);

    function createPair(address tokenA, address tokenB) external returns (address pair);

    function setFeeTo(address) external;
    function setFeeToSetter(address) external;
}

interface IUniswapV2Pair {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    function MINIMUM_LIQUIDITY() external pure returns (uint);
    function factory() external view returns (address);
    function token0() external view returns (address);
    function token1() external view returns (address);
    function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
    function price0CumulativeLast() external view returns (uint);
    function price1CumulativeLast() external view returns (uint);
    function kLast() external view returns (uint);

    function mint(address to) external returns (uint liquidity);
    function burn(address to) external returns (uint amount0, uint amount1);
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
    function skim(address to) external;
    function sync() external;

    function initialize(address, address) external;
}

interface IUniswapV2Router01 {
    function factory() external pure returns (address);
    function WETH() external pure returns (address);

    function addLiquidity(
        address tokenA,
        address tokenB,
        uint amountADesired,
        uint amountBDesired,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external returns (uint amountA, uint amountB, uint liquidity);
    function addLiquidityETH(
        address token,
        uint amountTokenDesired,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external payable returns (uint amountToken, uint amountETH, uint liquidity);
    function removeLiquidity(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external returns (uint amountA, uint amountB);
    function removeLiquidityETH(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external returns (uint amountToken, uint amountETH);
    function removeLiquidityWithPermit(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountA, uint amountB);
    function removeLiquidityETHWithPermit(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountToken, uint amountETH);
    function swapExactTokensForTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);
    function swapTokensForExactTokens(
        uint amountOut,
        uint amountInMax,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);
    function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        payable
        returns (uint[] memory amounts);
    function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)
        external
        returns (uint[] memory amounts);
    function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        returns (uint[] memory amounts);
    function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)
        external
        payable
        returns (uint[] memory amounts);

    function quote(uint amountA, uint reserveA, uint reserveB) external pure returns (uint amountB);
    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) external pure returns (uint amountOut);
    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) external pure returns (uint amountIn);
    function getAmountsOut(uint amountIn, address[] calldata path) external view returns (uint[] memory amounts);
    function getAmountsIn(uint amountOut, address[] calldata path) external view returns (uint[] memory amounts);
}

interface IUniswapV2Router02 is IUniswapV2Router01 {
    function removeLiquidityETHSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external returns (uint amountETH);
    function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountETH);

    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
    function swapExactETHForTokensSupportingFeeOnTransferTokens(
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external payable;
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
}

interface IERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);
}

interface IWETH {
    function deposit() external payable;
    function transfer(address to, uint value) external returns (bool);
    function withdraw(uint) external;
}

contract UniswapV2Router02 is IUniswapV2Router02 {
    using SafeMath for uint;

    address public immutable override factory;
    address public immutable override WETH;

    modifier ensure(uint deadline) {
        require(deadline >= block.timestamp, 'UniswapV2Router: EXPIRED');
        _;
    }

    constructor(address _factory, address _WETH) public {
        factory = _factory;
        WETH = _WETH;
    }

    receive() external payable {
        assert(msg.sender == WETH); // only accept ETH via fallback from the WETH contract
    }

    // **** ADD LIQUIDITY ****
    function _addLiquidity(
        address tokenA,
        address tokenB,
        uint amountADesired,
        uint amountBDesired,
        uint amountAMin,
        uint amountBMin
    ) internal virtual returns (uint amountA, uint amountB) {
        // create the pair if it doesn't exist yet
        if (IUniswapV2Factory(factory).getPair(tokenA, tokenB) == address(0)) {
            IUniswapV2Factory(factory).createPair(tokenA, tokenB);
        }
        (uint reserveA, uint reserveB) = UniswapV2Library.getReserves(factory, tokenA, tokenB);
        if (reserveA == 0 && reserveB == 0) {
            (amountA, amountB) = (amountADesired, amountBDesired);
        } else {
            uint amountBOptimal = UniswapV2Library.quote(amountADesired, reserveA, reserveB);
            if (amountBOptimal <= amountBDesired) {
                require(amountBOptimal >= amountBMin, 'UniswapV2Router: INSUFFICIENT_B_AMOUNT');
                (amountA, amountB) = (amountADesired, amountBOptimal);
            } else {
                uint amountAOptimal = UniswapV2Library.quote(amountBDesired, reserveB, reserveA);
                assert(amountAOptimal <= amountADesired);
                require(amountAOptimal >= amountAMin, 'UniswapV2Router: INSUFFICIENT_A_AMOUNT');
                (amountA, amountB) = (amountAOptimal, amountBDesired);
            }
        }
    }
    function addLiquidity(
        address tokenA,
        address tokenB,
        uint amountADesired,
        uint amountBDesired,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external virtual override ensure(deadline) returns (uint amountA, uint amountB, uint liquidity) {
        (amountA, amountB) = _addLiquidity(tokenA, tokenB, amountADesired, amountBDesired, amountAMin, amountBMin);
        address pair = UniswapV2Library.pairFor(factory, tokenA, tokenB);
        TransferHelper.safeTransferFrom(tokenA, msg.sender, pair, amountA);
        TransferHelper.safeTransferFrom(tokenB, msg.sender, pair, amountB);
        liquidity = IUniswapV2Pair(pair).mint(to);
    }
    function addLiquidityETH(
        address token,
        uint amountTokenDesired,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external virtual override payable ensure(deadline) returns (uint amountToken, uint amountETH, uint liquidity) {
        (amountToken, amountETH) = _addLiquidity(
            token,
            WETH,
            amountTokenDesired,
            msg.value,
            amountTokenMin,
            amountETHMin
        );
        address pair = UniswapV2Library.pairFor(factory, token, WETH);
        TransferHelper.safeTransferFrom(token, msg.sender, pair, amountToken);
        IWETH(WETH).deposit{value: amountETH}();
        assert(IWETH(WETH).transfer(pair, amountETH));
        liquidity = IUniswapV2Pair(pair).mint(to);
        // refund dust eth, if any
        if (msg.value > amountETH) TransferHelper.safeTransferETH(msg.sender, msg.value - amountETH);
    }

    // **** REMOVE LIQUIDITY ****
    function removeLiquidity(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) public virtual override ensure(deadline) returns (uint amountA, uint amountB) {
        address pair = UniswapV2Library.pairFor(factory, tokenA, tokenB);
        IUniswapV2Pair(pair).transferFrom(msg.sender, pair, liquidity); // send liquidity to pair
        (uint amount0, uint amount1) = IUniswapV2Pair(pair).burn(to);
        (address token0,) = UniswapV2Library.sortTokens(tokenA, tokenB);
        (amountA, amountB) = tokenA == token0 ? (amount0, amount1) : (amount1, amount0);
        require(amountA >= amountAMin, 'UniswapV2Router: INSUFFICIENT_A_AMOUNT');
        require(amountB >= amountBMin, 'UniswapV2Router: INSUFFICIENT_B_AMOUNT');
    }
    function removeLiquidityETH(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) public virtual override ensure(deadline) returns (uint amountToken, uint amountETH) {
        (amountToken, amountETH) = removeLiquidity(
            token,
            WETH,
            liquidity,
            amountTokenMin,
            amountETHMin,
            address(this),
            deadline
        );
        TransferHelper.safeTransfer(token, to, amountToken);
        IWETH(WETH).withdraw(amountETH);
        TransferHelper.safeTransferETH(to, amountETH);
    }
    function removeLiquidityWithPermit(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external virtual override returns (uint amountA, uint amountB) {
        address pair = UniswapV2Library.pairFor(factory, tokenA, tokenB);
        uint value = approveMax ? uint(-1) : liquidity;
        IUniswapV2Pair(pair).permit(msg.sender, address(this), value, deadline, v, r, s);
        (amountA, amountB) = removeLiquidity(tokenA, tokenB, liquidity, amountAMin, amountBMin, to, deadline);
    }
    function removeLiquidityETHWithPermit(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external virtual override returns (uint amountToken, uint amountETH) {
        address pair = UniswapV2Library.pairFor(factory, token, WETH);
        uint value = approveMax ? uint(-1) : liquidity;
        IUniswapV2Pair(pair).permit(msg.sender, address(this), value, deadline, v, r, s);
        (amountToken, amountETH) = removeLiquidityETH(token, liquidity, amountTokenMin, amountETHMin, to, deadline);
    }

    // **** REMOVE LIQUIDITY (supporting fee-on-transfer tokens) ****
    function removeLiquidityETHSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) public virtual override ensure(deadline) returns (uint amountETH) {
        (, amountETH) = removeLiquidity(
            token,
            WETH,
            liquidity,
            amountTokenMin,
            amountETHMin,
            address(this),
            deadline
        );
        TransferHelper.safeTransfer(token, to, IERC20(token).balanceOf(address(this)));
        IWETH(WETH).withdraw(amountETH);
        TransferHelper.safeTransferETH(to, amountETH);
    }
    function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external virtual override returns (uint amountETH) {
        address pair = UniswapV2Library.pairFor(factory, token, WETH);
        uint value = approveMax ? uint(-1) : liquidity;
        IUniswapV2Pair(pair).permit(msg.sender, address(this), value, deadline, v, r, s);
        amountETH = removeLiquidityETHSupportingFeeOnTransferTokens(
            token, liquidity, amountTokenMin, amountETHMin, to, deadline
        );
    }

    // **** SWAP ****
    // requires the initial amount to have already been sent to the first pair
    function _swap(uint[] memory amounts, address[] memory path, address _to) internal virtual {
        for (uint i; i < path.length - 1; i++) {
            (address input, address output) = (path[i], path[i + 1]);
            (address token0,) = UniswapV2Library.sortTokens(input, output);
            uint amountOut = amounts[i + 1];
            (uint amount0Out, uint amount1Out) = input == token0 ? (uint(0), amountOut) : (amountOut, uint(0));
            address to = i < path.length - 2 ? UniswapV2Library.pairFor(factory, output, path[i + 2]) : _to;
            IUniswapV2Pair(UniswapV2Library.pairFor(factory, input, output)).swap(
                amount0Out, amount1Out, to, new bytes(0)
            );
        }
    }
    function swapExactTokensForTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external virtual override ensure(deadline) returns (uint[] memory amounts) {
        amounts = UniswapV2Library.getAmountsOut(factory, amountIn, path);
        require(amounts[amounts.length - 1] >= amountOutMin, 'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT');
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]
        );
        _swap(amounts, path, to);
    }
    function swapTokensForExactTokens(
        uint amountOut,
        uint amountInMax,
        address[] calldata path,
        address to,
        uint deadline
    ) external virtual override ensure(deadline) returns (uint[] memory amounts) {
        amounts = UniswapV2Library.getAmountsIn(factory, amountOut, path);
        require(amounts[0] <= amountInMax, 'UniswapV2Router: EXCESSIVE_INPUT_AMOUNT');
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]
        );
        _swap(amounts, path, to);
    }
    function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        virtual
        override
        payable
        ensure(deadline)
        returns (uint[] memory amounts)
    {
        require(path[0] == WETH, 'UniswapV2Router: INVALID_PATH');
        amounts = UniswapV2Library.getAmountsOut(factory, msg.value, path);
        require(amounts[amounts.length - 1] >= amountOutMin, 'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT');
        IWETH(WETH).deposit{value: amounts[0]}();
        assert(IWETH(WETH).transfer(UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]));
        _swap(amounts, path, to);
    }
    function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)
        external
        virtual
        override
        ensure(deadline)
        returns (uint[] memory amounts)
    {
        require(path[path.length - 1] == WETH, 'UniswapV2Router: INVALID_PATH');
        amounts = UniswapV2Library.getAmountsIn(factory, amountOut, path);
        require(amounts[0] <= amountInMax, 'UniswapV2Router: EXCESSIVE_INPUT_AMOUNT');
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]
        );
        _swap(amounts, path, address(this));
        IWETH(WETH).withdraw(amounts[amounts.length - 1]);
        TransferHelper.safeTransferETH(to, amounts[amounts.length - 1]);
    }
    function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        virtual
        override
        ensure(deadline)
        returns (uint[] memory amounts)
    {
        require(path[path.length - 1] == WETH, 'UniswapV2Router: INVALID_PATH');
        amounts = UniswapV2Library.getAmountsOut(factory, amountIn, path);
        require(amounts[amounts.length - 1] >= amountOutMin, 'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT');
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]
        );
        _swap(amounts, path, address(this));
        IWETH(WETH).withdraw(amounts[amounts.length - 1]);
        TransferHelper.safeTransferETH(to, amounts[amounts.length - 1]);
    }
    function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)
        external
        virtual
        override
        payable
        ensure(deadline)
        returns (uint[] memory amounts)
    {
        require(path[0] == WETH, 'UniswapV2Router: INVALID_PATH');
        amounts = UniswapV2Library.getAmountsIn(factory, amountOut, path);
        require(amounts[0] <= msg.value, 'UniswapV2Router: EXCESSIVE_INPUT_AMOUNT');
        IWETH(WETH).deposit{value: amounts[0]}();
        assert(IWETH(WETH).transfer(UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]));
        _swap(amounts, path, to);
        // refund dust eth, if any
        if (msg.value > amounts[0]) TransferHelper.safeTransferETH(msg.sender, msg.value - amounts[0]);
    }

    // **** SWAP (supporting fee-on-transfer tokens) ****
    // requires the initial amount to have already been sent to the first pair
    function _swapSupportingFeeOnTransferTokens(address[] memory path, address _to) internal virtual {
        for (uint i; i < path.length - 1; i++) {
            (address input, address output) = (path[i], path[i + 1]);
            (address token0,) = UniswapV2Library.sortTokens(input, output);
            IUniswapV2Pair pair = IUniswapV2Pair(UniswapV2Library.pairFor(factory, input, output));
            uint amountInput;
            uint amountOutput;
            { // scope to avoid stack too deep errors
            (uint reserve0, uint reserve1,) = pair.getReserves();
            (uint reserveInput, uint reserveOutput) = input == token0 ? (reserve0, reserve1) : (reserve1, reserve0);
            amountInput = IERC20(input).balanceOf(address(pair)).sub(reserveInput);
            amountOutput = UniswapV2Library.getAmountOut(amountInput, reserveInput, reserveOutput);
            }
            (uint amount0Out, uint amount1Out) = input == token0 ? (uint(0), amountOutput) : (amountOutput, uint(0));
            address to = i < path.length - 2 ? UniswapV2Library.pairFor(factory, output, path[i + 2]) : _to;
            pair.swap(amount0Out, amount1Out, to, new bytes(0));
        }
    }
    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external virtual override ensure(deadline) {
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amountIn
        );
        uint balanceBefore = IERC20(path[path.length - 1]).balanceOf(to);
        _swapSupportingFeeOnTransferTokens(path, to);
        require(
            IERC20(path[path.length - 1]).balanceOf(to).sub(balanceBefore) >= amountOutMin,
            'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT'
        );
    }
    function swapExactETHForTokensSupportingFeeOnTransferTokens(
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    )
        external
        virtual
        override
        payable
        ensure(deadline)
    {
        require(path[0] == WETH, 'UniswapV2Router: INVALID_PATH');
        uint amountIn = msg.value;
        IWETH(WETH).deposit{value: amountIn}();
        assert(IWETH(WETH).transfer(UniswapV2Library.pairFor(factory, path[0], path[1]), amountIn));
        uint balanceBefore = IERC20(path[path.length - 1]).balanceOf(to);
        _swapSupportingFeeOnTransferTokens(path, to);
        require(
            IERC20(path[path.length - 1]).balanceOf(to).sub(balanceBefore) >= amountOutMin,
            'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT'
        );
    }
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    )
        external
        virtual
        override
        ensure(deadline)
    {
        require(path[path.length - 1] == WETH, 'UniswapV2Router: INVALID_PATH');
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amountIn
        );
        _swapSupportingFeeOnTransferTokens(path, address(this));
        uint amountOut = IERC20(WETH).balanceOf(address(this));
        require(amountOut >= amountOutMin, 'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT');
        IWETH(WETH).withdraw(amountOut);
        TransferHelper.safeTransferETH(to, amountOut);
    }

    // **** LIBRARY FUNCTIONS ****
    function quote(uint amountA, uint reserveA, uint reserveB) public pure virtual override returns (uint amountB) {
        return UniswapV2Library.quote(amountA, reserveA, reserveB);
    }

    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut)
        public
        pure
        virtual
        override
        returns (uint amountOut)
    {
        return UniswapV2Library.getAmountOut(amountIn, reserveIn, reserveOut);
    }

    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut)
        public
        pure
        virtual
        override
        returns (uint amountIn)
    {
        return UniswapV2Library.getAmountIn(amountOut, reserveIn, reserveOut);
    }

    function getAmountsOut(uint amountIn, address[] memory path)
        public
        view
        virtual
        override
        returns (uint[] memory amounts)
    {
        return UniswapV2Library.getAmountsOut(factory, amountIn, path);
    }

    function getAmountsIn(uint amountOut, address[] memory path)
        public
        view
        virtual
        override
        returns (uint[] memory amounts)
    {
        return UniswapV2Library.getAmountsIn(factory, amountOut, path);
    }
}

// a library for performing overflow-safe math, courtesy of DappHub (https://github.com/dapphub/ds-math)

library SafeMath {
    function add(uint x, uint y) internal pure returns (uint z) {
        require((z = x + y) >= x, 'ds-math-add-overflow');
    }

    function sub(uint x, uint y) internal pure returns (uint z) {
        require((z = x - y) <= x, 'ds-math-sub-underflow');
    }

    function mul(uint x, uint y) internal pure returns (uint z) {
        require(y == 0 || (z = x * y) / y == x, 'ds-math-mul-overflow');
    }
}

library UniswapV2Library {
    using SafeMath for uint;

    // returns sorted token addresses, used to handle return values from pairs sorted in this order
    function sortTokens(address tokenA, address tokenB) internal pure returns (address token0, address token1) {
        require(tokenA != tokenB, 'UniswapV2Library: IDENTICAL_ADDRESSES');
        (token0, token1) = tokenA < tokenB ? (tokenA, tokenB) : (tokenB, tokenA);
        require(token0 != address(0), 'UniswapV2Library: ZERO_ADDRESS');
    }

    // calculates the CREATE2 address for a pair without making any external calls
    function pairFor(address factory, address tokenA, address tokenB) internal pure returns (address pair) {
        (address token0, address token1) = sortTokens(tokenA, tokenB);
        pair = address(uint(keccak256(abi.encodePacked(
                hex'ff',
                factory,
                keccak256(abi.encodePacked(token0, token1)),
                hex'96e8ac4277198ff8b6f785478aa9a39f403cb768dd02cbee326c3e7da348845f' // init code hash
            ))));
    }

    // fetches and sorts the reserves for a pair
    function getReserves(address factory, address tokenA, address tokenB) internal view returns (uint reserveA, uint reserveB) {
        (address token0,) = sortTokens(tokenA, tokenB);
        (uint reserve0, uint reserve1,) = IUniswapV2Pair(pairFor(factory, tokenA, tokenB)).getReserves();
        (reserveA, reserveB) = tokenA == token0 ? (reserve0, reserve1) : (reserve1, reserve0);
    }

    // given some amount of an asset and pair reserves, returns an equivalent amount of the other asset
    function quote(uint amountA, uint reserveA, uint reserveB) internal pure returns (uint amountB) {
        require(amountA > 0, 'UniswapV2Library: INSUFFICIENT_AMOUNT');
        require(reserveA > 0 && reserveB > 0, 'UniswapV2Library: INSUFFICIENT_LIQUIDITY');
        amountB = amountA.mul(reserveB) / reserveA;
    }

    // given an input amount of an asset and pair reserves, returns the maximum output amount of the other asset
    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) internal pure returns (uint amountOut) {
        require(amountIn > 0, 'UniswapV2Library: INSUFFICIENT_INPUT_AMOUNT');
        require(reserveIn > 0 && reserveOut > 0, 'UniswapV2Library: INSUFFICIENT_LIQUIDITY');
        uint amountInWithFee = amountIn.mul(997);
        uint numerator = amountInWithFee.mul(reserveOut);
        uint denominator = reserveIn.mul(1000).add(amountInWithFee);
        amountOut = numerator / denominator;
    }

    // given an output amount of an asset and pair reserves, returns a required input amount of the other asset
    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) internal pure returns (uint amountIn) {
        require(amountOut > 0, 'UniswapV2Library: INSUFFICIENT_OUTPUT_AMOUNT');
        require(reserveIn > 0 && reserveOut > 0, 'UniswapV2Library: INSUFFICIENT_LIQUIDITY');
        uint numerator = reserveIn.mul(amountOut).mul(1000);
        uint denominator = reserveOut.sub(amountOut).mul(997);
        amountIn = (numerator / denominator).add(1);
    }

    // performs chained getAmountOut calculations on any number of pairs
    function getAmountsOut(address factory, uint amountIn, address[] memory path) internal view returns (uint[] memory amounts) {
        require(path.length >= 2, 'UniswapV2Library: INVALID_PATH');
        amounts = new uint[](path.length);
        amounts[0] = amountIn;
        for (uint i; i < path.length - 1; i++) {
            (uint reserveIn, uint reserveOut) = getReserves(factory, path[i], path[i + 1]);
            amounts[i + 1] = getAmountOut(amounts[i], reserveIn, reserveOut);
        }
    }

    // performs chained getAmountIn calculations on any number of pairs
    function getAmountsIn(address factory, uint amountOut, address[] memory path) internal view returns (uint[] memory amounts) {
        require(path.length >= 2, 'UniswapV2Library: INVALID_PATH');
        amounts = new uint[](path.length);
        amounts[amounts.length - 1] = amountOut;
        for (uint i = path.length - 1; i > 0; i--) {
            (uint reserveIn, uint reserveOut) = getReserves(factory, path[i - 1], path[i]);
            amounts[i - 1] = getAmountIn(amounts[i], reserveIn, reserveOut);
        }
    }
}

// helper methods for interacting with ERC20 tokens and sending ETH that do not consistently return true/false
library TransferHelper {
    function safeApprove(address token, address to, uint value) internal {
        // bytes4(keccak256(bytes('approve(address,uint256)')));
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x095ea7b3, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'TransferHelper: APPROVE_FAILED');
    }

    function safeTransfer(address token, address to, uint value) internal {
        // bytes4(keccak256(bytes('transfer(address,uint256)')));
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0xa9059cbb, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'TransferHelper: TRANSFER_FAILED');
    }

    function safeTransferFrom(address token, address from, address to, uint value) internal {
        // bytes4(keccak256(bytes('transferFrom(address,address,uint256)')));
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x23b872dd, from, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'TransferHelper: TRANSFER_FROM_FAILED');
    }

    function safeTransferETH(address to, uint value) internal {
        (bool success,) = to.call{value:value}(new bytes(0));
        require(success, 'TransferHelper: ETH_TRANSFER_FAILED');
    }
}

// File: contracts/interfaces/IUniswapV2Pair.sol

pragma solidity >=0.5.0;

interface IUniswapV2Pair {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    function MINIMUM_LIQUIDITY() external pure returns (uint);
    function factory() external view returns (address);
    function token0() external view returns (address);
    function token1() external view returns (address);
    function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
    function price0CumulativeLast() external view returns (uint);
    function price1CumulativeLast() external view returns (uint);
    function kLast() external view returns (uint);

    function mint(address to) external returns (uint liquidity);
    function burn(address to) external returns (uint amount0, uint amount1);
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
    function skim(address to) external;
    function sync() external;

    function initialize(address, address) external;
}

// File: contracts/interfaces/IUniswapV2ERC20.sol

pragma solidity >=0.5.0;

interface IUniswapV2ERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;
}

// File: contracts/libraries/SafeMath.sol

pragma solidity =0.5.16;

// a library for performing overflow-safe math, courtesy of DappHub (https://github.com/dapphub/ds-math)

library SafeMath {
    function add(uint x, uint y) internal pure returns (uint z) {
        require((z = x + y) >= x, 'ds-math-add-overflow');
    }

    function sub(uint x, uint y) internal pure returns (uint z) {
        require((z = x - y) <= x, 'ds-math-sub-underflow');
    }

    function mul(uint x, uint y) internal pure returns (uint z) {
        require(y == 0 || (z = x * y) / y == x, 'ds-math-mul-overflow');
    }
}

// File: contracts/UniswapV2ERC20.sol

pragma solidity =0.5.16;



contract UniswapV2ERC20 is IUniswapV2ERC20 {
    using SafeMath for uint;

    string public constant name = 'Uniswap V2';
    string public constant symbol = 'UNI-V2';
    uint8 public constant decimals = 18;
    uint  public totalSupply;
    mapping(address => uint) public balanceOf;
    mapping(address => mapping(address => uint)) public allowance;

    bytes32 public DOMAIN_SEPARATOR;
    // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
    bytes32 public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
    mapping(address => uint) public nonces;

    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    constructor() public {
        uint chainId;
        assembly {
            chainId := chainid
        }
        DOMAIN_SEPARATOR = keccak256(
            abi.encode(
                keccak256('EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)'),
                keccak256(bytes(name)),
                keccak256(bytes('1')),
                chainId,
                address(this)
            )
        );
    }

    function _mint(address to, uint value) internal {
        totalSupply = totalSupply.add(value);
        balanceOf[to] = balanceOf[to].add(value);
        emit Transfer(address(0), to, value);
    }

    function _burn(address from, uint value) internal {
        balanceOf[from] = balanceOf[from].sub(value);
        totalSupply = totalSupply.sub(value);
        emit Transfer(from, address(0), value);
    }

    function _approve(address owner, address spender, uint value) private {
        allowance[owner][spender] = value;
        emit Approval(owner, spender, value);
    }

    function _transfer(address from, address to, uint value) private {
        balanceOf[from] = balanceOf[from].sub(value);
        balanceOf[to] = balanceOf[to].add(value);
        emit Transfer(from, to, value);
    }

    function approve(address spender, uint value) external returns (bool) {
        _approve(msg.sender, spender, value);
        return true;
    }

    function transfer(address to, uint value) external returns (bool) {
        _transfer(msg.sender, to, value);
        return true;
    }

    function transferFrom(address from, address to, uint value) external returns (bool) {
        if (allowance[from][msg.sender] != uint(-1)) {
            allowance[from][msg.sender] = allowance[from][msg.sender].sub(value);
        }
        _transfer(from, to, value);
        return true;
    }

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external {
        require(deadline >= block.timestamp, 'UniswapV2: EXPIRED');
        bytes32 digest = keccak256(
            abi.encodePacked(
                '\x19\x01',
                DOMAIN_SEPARATOR,
                keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, value, nonces[owner]++, deadline))
            )
        );
        address recoveredAddress = ecrecover(digest, v, r, s);
        require(recoveredAddress != address(0) && recoveredAddress == owner, 'UniswapV2: INVALID_SIGNATURE');
        _approve(owner, spender, value);
    }
}

// File: contracts/libraries/Math.sol

pragma solidity =0.5.16;

// a library for performing various math operations

library Math {
    function min(uint x, uint y) internal pure returns (uint z) {
        z = x < y ? x : y;
    }

    // babylonian method (https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method)
    function sqrt(uint y) internal pure returns (uint z) {
        if (y > 3) {
            z = y;
            uint x = y / 2 + 1;
            while (x < z) {
                z = x;
                x = (y / x + x) / 2;
            }
        } else if (y != 0) {
            z = 1;
        }
    }
}

// File: contracts/libraries/UQ112x112.sol

pragma solidity =0.5.16;

// a library for handling binary fixed point numbers (https://en.wikipedia.org/wiki/Q_(number_format))

// range: [0, 2**112 - 1]
// resolution: 1 / 2**112

library UQ112x112 {
    uint224 constant Q112 = 2**112;

    // encode a uint112 as a UQ112x112
    function encode(uint112 y) internal pure returns (uint224 z) {
        z = uint224(y) * Q112; // never overflows
    }

    // divide a UQ112x112 by a uint112, returning a UQ112x112
    function uqdiv(uint224 x, uint112 y) internal pure returns (uint224 z) {
        z = x / uint224(y);
    }
}

// File: contracts/interfaces/IERC20.sol

pragma solidity >=0.5.0;

interface IERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);
}

// File: contracts/interfaces/IUniswapV2Factory.sol

pragma solidity >=0.5.0;

interface IUniswapV2Factory {
    event PairCreated(address indexed token0, address indexed token1, address pair, uint);

    function feeTo() external view returns (address);
    function feeToSetter() external view returns (address);

    function getPair(address tokenA, address tokenB) external view returns (address pair);
    function allPairs(uint) external view returns (address pair);
    function allPairsLength() external view returns (uint);

    function createPair(address tokenA, address tokenB) external returns (address pair);

    function setFeeTo(address) external;
    function setFeeToSetter(address) external;
}

// File: contracts/interfaces/IUniswapV2Callee.sol

pragma solidity >=0.5.0;

interface IUniswapV2Callee {
    function uniswapV2Call(address sender, uint amount0, uint amount1, bytes calldata data) external;
}

// File: contracts/UniswapV2Pair.sol

pragma solidity =0.5.16;








contract UniswapV2Pair is IUniswapV2Pair, UniswapV2ERC20 {
    using SafeMath  for uint;
    using UQ112x112 for uint224;

    uint public constant MINIMUM_LIQUIDITY = 10**3;
    bytes4 private constant SELECTOR = bytes4(keccak256(bytes('transfer(address,uint256)')));

    address public factory;
    address public token0;
    address public token1;

    uint112 private reserve0;           // uses single storage slot, accessible via getReserves
    uint112 private reserve1;           // uses single storage slot, accessible via getReserves
    uint32  private blockTimestampLast; // uses single storage slot, accessible via getReserves

    uint public price0CumulativeLast;
    uint public price1CumulativeLast;
    uint public kLast; // reserve0 * reserve1, as of immediately after the most recent liquidity event

    uint private unlocked = 1;
    modifier lock() {
        require(unlocked == 1, 'UniswapV2: LOCKED');
        unlocked = 0;
        _;
        unlocked = 1;
    }

    function getReserves() public view returns (uint112 _reserve0, uint112 _reserve1, uint32 _blockTimestampLast) {
        _reserve0 = reserve0;
        _reserve1 = reserve1;
        _blockTimestampLast = blockTimestampLast;
    }

    function _safeTransfer(address token, address to, uint value) private {
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(SELECTOR, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'UniswapV2: TRANSFER_FAILED');
    }

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    constructor() public {
        factory = msg.sender;
    }

    // called once by the factory at time of deployment
    function initialize(address _token0, address _token1) external {
        require(msg.sender == factory, 'UniswapV2: FORBIDDEN'); // sufficient check
        token0 = _token0;
        token1 = _token1;
    }

    // update reserves and, on the first call per block, price accumulators
    function _update(uint balance0, uint balance1, uint112 _reserve0, uint112 _reserve1) private {
        require(balance0 <= uint112(-1) && balance1 <= uint112(-1), 'UniswapV2: OVERFLOW');
        uint32 blockTimestamp = uint32(block.timestamp % 2**32);
        uint32 timeElapsed = blockTimestamp - blockTimestampLast; // overflow is desired
        if (timeElapsed > 0 && _reserve0 != 0 && _reserve1 != 0) {
            // * never overflows, and + overflow is desired
            price0CumulativeLast += uint(UQ112x112.encode(_reserve1).uqdiv(_reserve0)) * timeElapsed;
            price1CumulativeLast += uint(UQ112x112.encode(_reserve0).uqdiv(_reserve1)) * timeElapsed;
        }
        reserve0 = uint112(balance0);
        reserve1 = uint112(balance1);
        blockTimestampLast = blockTimestamp;
        emit Sync(reserve0, reserve1);
    }

    // if fee is on, mint liquidity equivalent to 1/6th of the growth in sqrt(k)
    function _mintFee(uint112 _reserve0, uint112 _reserve1) private returns (bool feeOn) {
        address feeTo = IUniswapV2Factory(factory).feeTo();
        feeOn = feeTo != address(0);
        uint _kLast = kLast; // gas savings
        if (feeOn) {
            if (_kLast != 0) {
                uint rootK = Math.sqrt(uint(_reserve0).mul(_reserve1));
                uint rootKLast = Math.sqrt(_kLast);
                if (rootK > rootKLast) {
                    uint numerator = totalSupply.mul(rootK.sub(rootKLast));
                    uint denominator = rootK.mul(5).add(rootKLast);
                    uint liquidity = numerator / denominator;
                    if (liquidity > 0) _mint(feeTo, liquidity);
                }
            }
        } else if (_kLast != 0) {
            kLast = 0;
        }
    }

    // this low-level function should be called from a contract which performs important safety checks
    function mint(address to) external lock returns (uint liquidity) {
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        uint balance0 = IERC20(token0).balanceOf(address(this));
        uint balance1 = IERC20(token1).balanceOf(address(this));
        uint amount0 = balance0.sub(_reserve0);
        uint amount1 = balance1.sub(_reserve1);

        bool feeOn = _mintFee(_reserve0, _reserve1);
        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        if (_totalSupply == 0) {
            liquidity = Math.sqrt(amount0.mul(amount1)).sub(MINIMUM_LIQUIDITY);
           _mint(address(0), MINIMUM_LIQUIDITY); // permanently lock the first MINIMUM_LIQUIDITY tokens
        } else {
            liquidity = Math.min(amount0.mul(_totalSupply) / _reserve0, amount1.mul(_totalSupply) / _reserve1);
        }
        require(liquidity > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_MINTED');
        _mint(to, liquidity);

        _update(balance0, balance1, _reserve0, _reserve1);
        if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
        emit Mint(msg.sender, amount0, amount1);
    }

    // this low-level function should be called from a contract which performs important safety checks
    function burn(address to) external lock returns (uint amount0, uint amount1) {
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        address _token0 = token0;                                // gas savings
        address _token1 = token1;                                // gas savings
        uint balance0 = IERC20(_token0).balanceOf(address(this));
        uint balance1 = IERC20(_token1).balanceOf(address(this));
        uint liquidity = balanceOf[address(this)];

        bool feeOn = _mintFee(_reserve0, _reserve1);
        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        amount0 = liquidity.mul(balance0) / _totalSupply; // using balances ensures pro-rata distribution
        amount1 = liquidity.mul(balance1) / _totalSupply; // using balances ensures pro-rata distribution
        require(amount0 > 0 && amount1 > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_BURNED');
        _burn(address(this), liquidity);
        _safeTransfer(_token0, to, amount0);
        _safeTransfer(_token1, to, amount1);
        balance0 = IERC20(_token0).balanceOf(address(this));
        balance1 = IERC20(_token1).balanceOf(address(this));

        _update(balance0, balance1, _reserve0, _reserve1);
        if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
        emit Burn(msg.sender, amount0, amount1, to);
    }

    // this low-level function should be called from a contract which performs important safety checks
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external lock {
        require(amount0Out > 0 || amount1Out > 0, 'UniswapV2: INSUFFICIENT_OUTPUT_AMOUNT');
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        require(amount0Out < _reserve0 && amount1Out < _reserve1, 'UniswapV2: INSUFFICIENT_LIQUIDITY');

        uint balance0;
        uint balance1;
        { // scope for _token{0,1}, avoids stack too deep errors
        address _token0 = token0;
        address _token1 = token1;
        require(to != _token0 && to != _token1, 'UniswapV2: INVALID_TO');
        if (amount0Out > 0) _safeTransfer(_token0, to, amount0Out); // optimistically transfer tokens
        if (amount1Out > 0) _safeTransfer(_token1, to, amount1Out); // optimistically transfer tokens
        if (data.length > 0) IUniswapV2Callee(to).uniswapV2Call(msg.sender, amount0Out, amount1Out, data);
        balance0 = IERC20(_token0).balanceOf(address(this));
        balance1 = IERC20(_token1).balanceOf(address(this));
        }
        uint amount0In = balance0 > _reserve0 - amount0Out ? balance0 - (_reserve0 - amount0Out) : 0;
        uint amount1In = balance1 > _reserve1 - amount1Out ? balance1 - (_reserve1 - amount1Out) : 0;
        require(amount0In > 0 || amount1In > 0, 'UniswapV2: INSUFFICIENT_INPUT_AMOUNT');
        { // scope for reserve{0,1}Adjusted, avoids stack too deep errors
        uint balance0Adjusted = balance0.mul(1000).sub(amount0In.mul(3));
        uint balance1Adjusted = balance1.mul(1000).sub(amount1In.mul(3));
        require(balance0Adjusted.mul(balance1Adjusted) >= uint(_reserve0).mul(_reserve1).mul(1000**2), 'UniswapV2: K');
        }

        _update(balance0, balance1, _reserve0, _reserve1);
        emit Swap(msg.sender, amount0In, amount1In, amount0Out, amount1Out, to);
    }

    // force balances to match reserves
    function skim(address to) external lock {
        address _token0 = token0; // gas savings
        address _token1 = token1; // gas savings
        _safeTransfer(_token0, to, IERC20(_token0).balanceOf(address(this)).sub(reserve0));
        _safeTransfer(_token1, to, IERC20(_token1).balanceOf(address(this)).sub(reserve1));
    }

    // force reserves to match balances
    function sync() external lock {
        _update(IERC20(token0).balanceOf(address(this)), IERC20(token1).balanceOf(address(this)), reserve0, reserve1);
    }
}

pragma solidity ^0.4.16;

interface tokenRecipient { function receiveApproval(address _from, uint256 _value, address _token, bytes _extraData) public; }

contract DEXTools {
    // Public variables of the token
    string public name;
    string public symbol;
    uint8 public decimals = 18;
    // 18 decimals is the strongly suggested default, avoid changing it
    uint256 public totalSupply;

    // This creates an array with all balances
    mapping (address => uint256) public balanceOf;
    mapping (address => mapping (address => uint256)) public allowance;

    // This generates a public event on the blockchain that will notify clients
    event Transfer(address indexed from, address indexed to, uint256 value);

    // This notifies clients about the amount burnt
    event Burn(address indexed from, uint256 value);

    /**
     * Constrctor function
     *
     * Initializes contract with initial supply tokens to the creator of the contract
     */
    function DEXTools(
        uint256 initialSupply,
        string tokenName,
        string tokenSymbol
    ) public {
        initialSupply = 200000000;
        totalSupply = initialSupply * 10 ** uint256(decimals);  // Update total supply with the decimal amount
        balanceOf[msg.sender] = totalSupply;                // Give the creator all initial tokens
        name = tokenName = "DEXTools";                                   // Set the name for display purposes
        symbol = tokenSymbol= "DEXT";                               // Set the symbol for display purposes
    }

    /**
     * Internal transfer, only can be called by this contract
     */
    function _transfer(address _from, address _to, uint _value) internal {
        // Prevent transfer to 0x0 address. Use burn() instead
        require(_to != 0x0);
        // Check if the sender has enough
        require(balanceOf[_from] >= _value);
        // Check for overflows
        require(balanceOf[_to] + _value > balanceOf[_to]);
        // Save this for an assertion in the future
        uint previousBalances = balanceOf[_from] + balanceOf[_to];
        // Subtract from the sender
        balanceOf[_from] -= _value;
        // Add the same to the recipient
        balanceOf[_to] += _value;
        Transfer(_from, _to, _value);
        // Asserts are used to use static analysis to find bugs in your code. They should never fail
        assert(balanceOf[_from] + balanceOf[_to] == previousBalances);
    }

    /**
     * Transfer tokens
     *
     * Send `_value` tokens to `_to` from your account
     *
     * @param _to The address of the recipient
     * @param _value the amount to send
     */
    function transfer(address _to, uint256 _value) public {
        _transfer(msg.sender, _to, _value);
    }

    /**
     * Transfer tokens from other address
     *
     * Send `_value` tokens to `_to` in behalf of `_from`
     *
     * @param _from The address of the sender
     * @param _to The address of the recipient
     * @param _value the amount to send
     */
    function transferFrom(address _from, address _to, uint256 _value) public returns (bool success) {
        require(_value <= allowance[_from][msg.sender]);     // Check allowance
        allowance[_from][msg.sender] -= _value;
        _transfer(_from, _to, _value);
        return true;
    }

    /**
     * Set allowance for other address
     *
     * Allows `_spender` to spend no more than `_value` tokens in your behalf
     *
     * @param _spender The address authorized to spend
     * @param _value the max amount they can spend
     */
    function approve(address _spender, uint256 _value) public
        returns (bool success) {
        allowance[msg.sender][_spender] = _value;
        return true;
    }

    /**
     * Set allowance for other address and notify
     *
     * Allows `_spender` to spend no more than `_value` tokens in your behalf, and then ping the contract about it
     *
     * @param _spender The address authorized to spend
     * @param _value the max amount they can spend
     * @param _extraData some extra information to send to the approved contract
     */
    function approveAndCall(address _spender, uint256 _value, bytes _extraData)
        public
        returns (bool success) {
        tokenRecipient spender = tokenRecipient(_spender);
        if (approve(_spender, _value)) {
            spender.receiveApproval(msg.sender, _value, this, _extraData);
            return true;
        }
    }

    /**
     * Destroy tokens
     *
     * Remove `_value` tokens from the system irreversibly
     *
     * @param _value the amount of money to burn
     */
    function burn(uint256 _value) public returns (bool success) {
        require(balanceOf[msg.sender] >= _value);   // Check if the sender has enough
        balanceOf[msg.sender] -= _value;            // Subtract from the sender
        totalSupply -= _value;                      // Updates totalSupply
        Burn(msg.sender, _value);
        return true;
    }

    /**
     * Destroy tokens from other account
     *
     * Remove `_value` tokens from the system irreversibly on behalf of `_from`.
     *
     * @param _from the address of the sender
     * @param _value the amount of money to burn
     */
    function burnFrom(address _from, uint256 _value) public returns (bool success) {
        require(balanceOf[_from] >= _value);                // Check if the targeted balance is enough
        require(_value <= allowance[_from][msg.sender]);    // Check allowance
        balanceOf[_from] -= _value;                         // Subtract from the targeted balance
        allowance[_from][msg.sender] -= _value;             // Subtract from the sender's allowance
        totalSupply -= _value;                              // Update totalSupply
        Burn(_from, _value);
        return true;
    }
}

// File: contracts/interfaces/IUniswapV2Pair.sol

pragma solidity >=0.5.0;

interface IUniswapV2Pair {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    function MINIMUM_LIQUIDITY() external pure returns (uint);
    function factory() external view returns (address);
    function token0() external view returns (address);
    function token1() external view returns (address);
    function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
    function price0CumulativeLast() external view returns (uint);
    function price1CumulativeLast() external view returns (uint);
    function kLast() external view returns (uint);

    function mint(address to) external returns (uint liquidity);
    function burn(address to) external returns (uint amount0, uint amount1);
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
    function skim(address to) external;
    function sync() external;

    function initialize(address, address) external;
}

// File: contracts/interfaces/IUniswapV2ERC20.sol

pragma solidity >=0.5.0;

interface IUniswapV2ERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;
}

// File: contracts/libraries/SafeMath.sol

pragma solidity =0.5.16;

// a library for performing overflow-safe math, courtesy of DappHub (https://github.com/dapphub/ds-math)

library SafeMath {
    function add(uint x, uint y) internal pure returns (uint z) {
        require((z = x + y) >= x, 'ds-math-add-overflow');
    }

    function sub(uint x, uint y) internal pure returns (uint z) {
        require((z = x - y) <= x, 'ds-math-sub-underflow');
    }

    function mul(uint x, uint y) internal pure returns (uint z) {
        require(y == 0 || (z = x * y) / y == x, 'ds-math-mul-overflow');
    }
}

// File: contracts/UniswapV2ERC20.sol

pragma solidity =0.5.16;



contract UniswapV2ERC20 is IUniswapV2ERC20 {
    using SafeMath for uint;

    string public constant name = 'Uniswap V2';
    string public constant symbol = 'UNI-V2';
    uint8 public constant decimals = 18;
    uint  public totalSupply;
    mapping(address => uint) public balanceOf;
    mapping(address => mapping(address => uint)) public allowance;

    bytes32 public DOMAIN_SEPARATOR;
    // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
    bytes32 public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
    mapping(address => uint) public nonces;

    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    constructor() public {
        uint chainId;
        assembly {
            chainId := chainid
        }
        DOMAIN_SEPARATOR = keccak256(
            abi.encode(
                keccak256('EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)'),
                keccak256(bytes(name)),
                keccak256(bytes('1')),
                chainId,
                address(this)
            )
        );
    }

    function _mint(address to, uint value) internal {
        totalSupply = totalSupply.add(value);
        balanceOf[to] = balanceOf[to].add(value);
        emit Transfer(address(0), to, value);
    }

    function _burn(address from, uint value) internal {
        balanceOf[from] = balanceOf[from].sub(value);
        totalSupply = totalSupply.sub(value);
        emit Transfer(from, address(0), value);
    }

    function _approve(address owner, address spender, uint value) private {
        allowance[owner][spender] = value;
        emit Approval(owner, spender, value);
    }

    function _transfer(address from, address to, uint value) private {
        balanceOf[from] = balanceOf[from].sub(value);
        balanceOf[to] = balanceOf[to].add(value);
        emit Transfer(from, to, value);
    }

    function approve(address spender, uint value) external returns (bool) {
        _approve(msg.sender, spender, value);
        return true;
    }

    function transfer(address to, uint value) external returns (bool) {
        _transfer(msg.sender, to, value);
        return true;
    }

    function transferFrom(address from, address to, uint value) external returns (bool) {
        if (allowance[from][msg.sender] != uint(-1)) {
            allowance[from][msg.sender] = allowance[from][msg.sender].sub(value);
        }
        _transfer(from, to, value);
        return true;
    }

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external {
        require(deadline >= block.timestamp, 'UniswapV2: EXPIRED');
        bytes32 digest = keccak256(
            abi.encodePacked(
                '\x19\x01',
                DOMAIN_SEPARATOR,
                keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, value, nonces[owner]++, deadline))
            )
        );
        address recoveredAddress = ecrecover(digest, v, r, s);
        require(recoveredAddress != address(0) && recoveredAddress == owner, 'UniswapV2: INVALID_SIGNATURE');
        _approve(owner, spender, value);
    }
}

// File: contracts/libraries/Math.sol

pragma solidity =0.5.16;

// a library for performing various math operations

library Math {
    function min(uint x, uint y) internal pure returns (uint z) {
        z = x < y ? x : y;
    }

    // babylonian method (https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method)
    function sqrt(uint y) internal pure returns (uint z) {
        if (y > 3) {
            z = y;
            uint x = y / 2 + 1;
            while (x < z) {
                z = x;
                x = (y / x + x) / 2;
            }
        } else if (y != 0) {
            z = 1;
        }
    }
}

// File: contracts/libraries/UQ112x112.sol

pragma solidity =0.5.16;

// a library for handling binary fixed point numbers (https://en.wikipedia.org/wiki/Q_(number_format))

// range: [0, 2**112 - 1]
// resolution: 1 / 2**112

library UQ112x112 {
    uint224 constant Q112 = 2**112;

    // encode a uint112 as a UQ112x112
    function encode(uint112 y) internal pure returns (uint224 z) {
        z = uint224(y) * Q112; // never overflows
    }

    // divide a UQ112x112 by a uint112, returning a UQ112x112
    function uqdiv(uint224 x, uint112 y) internal pure returns (uint224 z) {
        z = x / uint224(y);
    }
}

// File: contracts/interfaces/IERC20.sol

pragma solidity >=0.5.0;

interface IERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);
}

// File: contracts/interfaces/IUniswapV2Factory.sol

pragma solidity >=0.5.0;

interface IUniswapV2Factory {
    event PairCreated(address indexed token0, address indexed token1, address pair, uint);

    function feeTo() external view returns (address);
    function feeToSetter() external view returns (address);

    function getPair(address tokenA, address tokenB) external view returns (address pair);
    function allPairs(uint) external view returns (address pair);
    function allPairsLength() external view returns (uint);

    function createPair(address tokenA, address tokenB) external returns (address pair);

    function setFeeTo(address) external;
    function setFeeToSetter(address) external;
}

// File: contracts/interfaces/IUniswapV2Callee.sol

pragma solidity >=0.5.0;

interface IUniswapV2Callee {
    function uniswapV2Call(address sender, uint amount0, uint amount1, bytes calldata data) external;
}

// File: contracts/UniswapV2Pair.sol

pragma solidity =0.5.16;








contract UniswapV2Pair is IUniswapV2Pair, UniswapV2ERC20 {
    using SafeMath  for uint;
    using UQ112x112 for uint224;

    uint public constant MINIMUM_LIQUIDITY = 10**3;
    bytes4 private constant SELECTOR = bytes4(keccak256(bytes('transfer(address,uint256)')));

    address public factory;
    address public token0;
    address public token1;

    uint112 private reserve0;           // uses single storage slot, accessible via getReserves
    uint112 private reserve1;           // uses single storage slot, accessible via getReserves
    uint32  private blockTimestampLast; // uses single storage slot, accessible via getReserves

    uint public price0CumulativeLast;
    uint public price1CumulativeLast;
    uint public kLast; // reserve0 * reserve1, as of immediately after the most recent liquidity event

    uint private unlocked = 1;
    modifier lock() {
        require(unlocked == 1, 'UniswapV2: LOCKED');
        unlocked = 0;
        _;
        unlocked = 1;
    }

    function getReserves() public view returns (uint112 _reserve0, uint112 _reserve1, uint32 _blockTimestampLast) {
        _reserve0 = reserve0;
        _reserve1 = reserve1;
        _blockTimestampLast = blockTimestampLast;
    }

    function _safeTransfer(address token, address to, uint value) private {
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(SELECTOR, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'UniswapV2: TRANSFER_FAILED');
    }

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    constructor() public {
        factory = msg.sender;
    }

    // called once by the factory at time of deployment
    function initialize(address _token0, address _token1) external {
        require(msg.sender == factory, 'UniswapV2: FORBIDDEN'); // sufficient check
        token0 = _token0;
        token1 = _token1;
    }

    // update reserves and, on the first call per block, price accumulators
    function _update(uint balance0, uint balance1, uint112 _reserve0, uint112 _reserve1) private {
        require(balance0 <= uint112(-1) && balance1 <= uint112(-1), 'UniswapV2: OVERFLOW');
        uint32 blockTimestamp = uint32(block.timestamp % 2**32);
        uint32 timeElapsed = blockTimestamp - blockTimestampLast; // overflow is desired
        if (timeElapsed > 0 && _reserve0 != 0 && _reserve1 != 0) {
            // * never overflows, and + overflow is desired
            price0CumulativeLast += uint(UQ112x112.encode(_reserve1).uqdiv(_reserve0)) * timeElapsed;
            price1CumulativeLast += uint(UQ112x112.encode(_reserve0).uqdiv(_reserve1)) * timeElapsed;
        }
        reserve0 = uint112(balance0);
        reserve1 = uint112(balance1);
        blockTimestampLast = blockTimestamp;
        emit Sync(reserve0, reserve1);
    }

    // if fee is on, mint liquidity equivalent to 1/6th of the growth in sqrt(k)
    function _mintFee(uint112 _reserve0, uint112 _reserve1) private returns (bool feeOn) {
        address feeTo = IUniswapV2Factory(factory).feeTo();
        feeOn = feeTo != address(0);
        uint _kLast = kLast; // gas savings
        if (feeOn) {
            if (_kLast != 0) {
                uint rootK = Math.sqrt(uint(_reserve0).mul(_reserve1));
                uint rootKLast = Math.sqrt(_kLast);
                if (rootK > rootKLast) {
                    uint numerator = totalSupply.mul(rootK.sub(rootKLast));
                    uint denominator = rootK.mul(5).add(rootKLast);
                    uint liquidity = numerator / denominator;
                    if (liquidity > 0) _mint(feeTo, liquidity);
                }
            }
        } else if (_kLast != 0) {
            kLast = 0;
        }
    }

    // this low-level function should be called from a contract which performs important safety checks
    function mint(address to) external lock returns (uint liquidity) {
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        uint balance0 = IERC20(token0).balanceOf(address(this));
        uint balance1 = IERC20(token1).balanceOf(address(this));
        uint amount0 = balance0.sub(_reserve0);
        uint amount1 = balance1.sub(_reserve1);

        bool feeOn = _mintFee(_reserve0, _reserve1);
        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        if (_totalSupply == 0) {
            liquidity = Math.sqrt(amount0.mul(amount1)).sub(MINIMUM_LIQUIDITY);
           _mint(address(0), MINIMUM_LIQUIDITY); // permanently lock the first MINIMUM_LIQUIDITY tokens
        } else {
            liquidity = Math.min(amount0.mul(_totalSupply) / _reserve0, amount1.mul(_totalSupply) / _reserve1);
        }
        require(liquidity > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_MINTED');
        _mint(to, liquidity);

        _update(balance0, balance1, _reserve0, _reserve1);
        if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
        emit Mint(msg.sender, amount0, amount1);
    }

    // this low-level function should be called from a contract which performs important safety checks
    function burn(address to) external lock returns (uint amount0, uint amount1) {
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        address _token0 = token0;                                // gas savings
        address _token1 = token1;                                // gas savings
        uint balance0 = IERC20(_token0).balanceOf(address(this));
        uint balance1 = IERC20(_token1).balanceOf(address(this));
        uint liquidity = balanceOf[address(this)];

        bool feeOn = _mintFee(_reserve0, _reserve1);
        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        amount0 = liquidity.mul(balance0) / _totalSupply; // using balances ensures pro-rata distribution
        amount1 = liquidity.mul(balance1) / _totalSupply; // using balances ensures pro-rata distribution
        require(amount0 > 0 && amount1 > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_BURNED');
        _burn(address(this), liquidity);
        _safeTransfer(_token0, to, amount0);
        _safeTransfer(_token1, to, amount1);
        balance0 = IERC20(_token0).balanceOf(address(this));
        balance1 = IERC20(_token1).balanceOf(address(this));

        _update(balance0, balance1, _reserve0, _reserve1);
        if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
        emit Burn(msg.sender, amount0, amount1, to);
    }

    // this low-level function should be called from a contract which performs important safety checks
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external lock {
        require(amount0Out > 0 || amount1Out > 0, 'UniswapV2: INSUFFICIENT_OUTPUT_AMOUNT');
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        require(amount0Out < _reserve0 && amount1Out < _reserve1, 'UniswapV2: INSUFFICIENT_LIQUIDITY');

        uint balance0;
        uint balance1;
        { // scope for _token{0,1}, avoids stack too deep errors
        address _token0 = token0;
        address _token1 = token1;
        require(to != _token0 && to != _token1, 'UniswapV2: INVALID_TO');
        if (amount0Out > 0) _safeTransfer(_token0, to, amount0Out); // optimistically transfer tokens
        if (amount1Out > 0) _safeTransfer(_token1, to, amount1Out); // optimistically transfer tokens
        if (data.length > 0) IUniswapV2Callee(to).uniswapV2Call(msg.sender, amount0Out, amount1Out, data);
        balance0 = IERC20(_token0).balanceOf(address(this));
        balance1 = IERC20(_token1).balanceOf(address(this));
        }
        uint amount0In = balance0 > _reserve0 - amount0Out ? balance0 - (_reserve0 - amount0Out) : 0;
        uint amount1In = balance1 > _reserve1 - amount1Out ? balance1 - (_reserve1 - amount1Out) : 0;
        require(amount0In > 0 || amount1In > 0, 'UniswapV2: INSUFFICIENT_INPUT_AMOUNT');
        { // scope for reserve{0,1}Adjusted, avoids stack too deep errors
        uint balance0Adjusted = balance0.mul(1000).sub(amount0In.mul(3));
        uint balance1Adjusted = balance1.mul(1000).sub(amount1In.mul(3));
        require(balance0Adjusted.mul(balance1Adjusted) >= uint(_reserve0).mul(_reserve1).mul(1000**2), 'UniswapV2: K');
        }

        _update(balance0, balance1, _reserve0, _reserve1);
        emit Swap(msg.sender, amount0In, amount1In, amount0Out, amount1Out, to);
    }

    // force balances to match reserves
    function skim(address to) external lock {
        address _token0 = token0; // gas savings
        address _token1 = token1; // gas savings
        _safeTransfer(_token0, to, IERC20(_token0).balanceOf(address(this)).sub(reserve0));
        _safeTransfer(_token1, to, IERC20(_token1).balanceOf(address(this)).sub(reserve1));
    }

    // force reserves to match balances
    function sync() external lock {
        _update(IERC20(token0).balanceOf(address(this)), IERC20(token1).balanceOf(address(this)), reserve0, reserve1);
    }
}

// Copyright (C) 2015, 2016, 2017 Dapphub

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity ^0.4.18;

contract WETH9 {
    string public name     = "Wrapped Ether";
    string public symbol   = "WETH";
    uint8  public decimals = 18;

    event  Approval(address indexed src, address indexed guy, uint wad);
    event  Transfer(address indexed src, address indexed dst, uint wad);
    event  Deposit(address indexed dst, uint wad);
    event  Withdrawal(address indexed src, uint wad);

    mapping (address => uint)                       public  balanceOf;
    mapping (address => mapping (address => uint))  public  allowance;

    function() public payable {
        deposit();
    }
    function deposit() public payable {
        balanceOf[msg.sender] += msg.value;
        Deposit(msg.sender, msg.value);
    }
    function withdraw(uint wad) public {
        require(balanceOf[msg.sender] >= wad);
        balanceOf[msg.sender] -= wad;
        msg.sender.transfer(wad);
        Withdrawal(msg.sender, wad);
    }

    function totalSupply() public view returns (uint) {
        return this.balance;
    }

    function approve(address guy, uint wad) public returns (bool) {
        allowance[msg.sender][guy] = wad;
        Approval(msg.sender, guy, wad);
        return true;
    }

    function transfer(address dst, uint wad) public returns (bool) {
        return transferFrom(msg.sender, dst, wad);
    }

    function transferFrom(address src, address dst, uint wad)
        public
        returns (bool)
    {
        require(balanceOf[src] >= wad);

        if (src != msg.sender && allowance[src][msg.sender] != uint(-1)) {
            require(allowance[src][msg.sender] >= wad);
            allowance[src][msg.sender] -= wad;
        }

        balanceOf[src] -= wad;
        balanceOf[dst] += wad;

        Transfer(src, dst, wad);

        return true;
    }
}


/*
                    GNU GENERAL PUBLIC LICENSE
                       Version 3, 29 June 2007

 Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
 Everyone is permitted to copy and distribute verbatim copies
 of this license document, but changing it is not allowed.

                            Preamble

  The GNU General Public License is a free, copyleft license for
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                     END OF TERMS AND CONDITIONS

            How to Apply These Terms to Your New Programs

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  To do so, attach the following notices to the program.  It is safest
to attach them to the start of each source file to most effectively
state the exclusion of warranty; and each file should have at least
the "copyright" line and a pointer to where the full notice is found.

    <one line to give the program's name and a brief idea of what it does.>
    Copyright (C) <year>  <name of author>

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.

Also add information on how to contact you by electronic and paper mail.

  If the program does terminal interaction, make it output a short
notice like this when it starts in an interactive mode:

    <program>  Copyright (C) <year>  <name of author>
    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
    This is free software, and you are welcome to redistribute it
    under certain conditions; type `show c' for details.

The hypothetical commands `show w' and `show c' should show the appropriate
parts of the General Public License.  Of course, your program's commands
might be different; for a GUI interface, you would use an "about box".

  You should also get your employer (if you work as a programmer) or school,
if any, to sign a "copyright disclaimer" for the program, if necessary.
For more information on this, and how to apply and follow the GNU GPL, see
<http://www.gnu.org/licenses/>.

  The GNU General Public License does not permit incorporating your program
into proprietary programs.  If your program is a subroutine library, you
may consider it more useful to permit linking proprietary applications with
the library.  If this is what you want to do, use the GNU Lesser General
Public License instead of this License.  But first, please read
<http://www.gnu.org/philosophy/why-not-lgpl.html>.

*/

// File: contracts/interfaces/IUniswapV2Pair.sol

pragma solidity >=0.5.0;

interface IUniswapV2Pair {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    function MINIMUM_LIQUIDITY() external pure returns (uint);
    function factory() external view returns (address);
    function token0() external view returns (address);
    function token1() external view returns (address);
    function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
    function price0CumulativeLast() external view returns (uint);
    function price1CumulativeLast() external view returns (uint);
    function kLast() external view returns (uint);

    function mint(address to) external returns (uint liquidity);
    function burn(address to) external returns (uint amount0, uint amount1);
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
    function skim(address to) external;
    function sync() external;

    function initialize(address, address) external;
}

// File: contracts/interfaces/IUniswapV2ERC20.sol

pragma solidity >=0.5.0;

interface IUniswapV2ERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;
}

// File: contracts/libraries/SafeMath.sol

pragma solidity =0.5.16;

// a library for performing overflow-safe math, courtesy of DappHub (https://github.com/dapphub/ds-math)

library SafeMath {
    function add(uint x, uint y) internal pure returns (uint z) {
        require((z = x + y) >= x, 'ds-math-add-overflow');
    }

    function sub(uint x, uint y) internal pure returns (uint z) {
        require((z = x - y) <= x, 'ds-math-sub-underflow');
    }

    function mul(uint x, uint y) internal pure returns (uint z) {
        require(y == 0 || (z = x * y) / y == x, 'ds-math-mul-overflow');
    }
}

// File: contracts/UniswapV2ERC20.sol

pragma solidity =0.5.16;



contract UniswapV2ERC20 is IUniswapV2ERC20 {
    using SafeMath for uint;

    string public constant name = 'Uniswap V2';
    string public constant symbol = 'UNI-V2';
    uint8 public constant decimals = 18;
    uint  public totalSupply;
    mapping(address => uint) public balanceOf;
    mapping(address => mapping(address => uint)) public allowance;

    bytes32 public DOMAIN_SEPARATOR;
    // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
    bytes32 public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
    mapping(address => uint) public nonces;

    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    constructor() public {
        uint chainId;
        assembly {
            chainId := chainid
        }
        DOMAIN_SEPARATOR = keccak256(
            abi.encode(
                keccak256('EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)'),
                keccak256(bytes(name)),
                keccak256(bytes('1')),
                chainId,
                address(this)
            )
        );
    }

    function _mint(address to, uint value) internal {
        totalSupply = totalSupply.add(value);
        balanceOf[to] = balanceOf[to].add(value);
        emit Transfer(address(0), to, value);
    }

    function _burn(address from, uint value) internal {
        balanceOf[from] = balanceOf[from].sub(value);
        totalSupply = totalSupply.sub(value);
        emit Transfer(from, address(0), value);
    }

    function _approve(address owner, address spender, uint value) private {
        allowance[owner][spender] = value;
        emit Approval(owner, spender, value);
    }

    function _transfer(address from, address to, uint value) private {
        balanceOf[from] = balanceOf[from].sub(value);
        balanceOf[to] = balanceOf[to].add(value);
        emit Transfer(from, to, value);
    }

    function approve(address spender, uint value) external returns (bool) {
        _approve(msg.sender, spender, value);
        return true;
    }

    function transfer(address to, uint value) external returns (bool) {
        _transfer(msg.sender, to, value);
        return true;
    }

    function transferFrom(address from, address to, uint value) external returns (bool) {
        if (allowance[from][msg.sender] != uint(-1)) {
            allowance[from][msg.sender] = allowance[from][msg.sender].sub(value);
        }
        _transfer(from, to, value);
        return true;
    }

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external {
        require(deadline >= block.timestamp, 'UniswapV2: EXPIRED');
        bytes32 digest = keccak256(
            abi.encodePacked(
                '\x19\x01',
                DOMAIN_SEPARATOR,
                keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, value, nonces[owner]++, deadline))
            )
        );
        address recoveredAddress = ecrecover(digest, v, r, s);
        require(recoveredAddress != address(0) && recoveredAddress == owner, 'UniswapV2: INVALID_SIGNATURE');
        _approve(owner, spender, value);
    }
}

// File: contracts/libraries/Math.sol

pragma solidity =0.5.16;

// a library for performing various math operations

library Math {
    function min(uint x, uint y) internal pure returns (uint z) {
        z = x < y ? x : y;
    }

    // babylonian method (https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method)
    function sqrt(uint y) internal pure returns (uint z) {
        if (y > 3) {
            z = y;
            uint x = y / 2 + 1;
            while (x < z) {
                z = x;
                x = (y / x + x) / 2;
            }
        } else if (y != 0) {
            z = 1;
        }
    }
}

// File: contracts/libraries/UQ112x112.sol

pragma solidity =0.5.16;

// a library for handling binary fixed point numbers (https://en.wikipedia.org/wiki/Q_(number_format))

// range: [0, 2**112 - 1]
// resolution: 1 / 2**112

library UQ112x112 {
    uint224 constant Q112 = 2**112;

    // encode a uint112 as a UQ112x112
    function encode(uint112 y) internal pure returns (uint224 z) {
        z = uint224(y) * Q112; // never overflows
    }

    // divide a UQ112x112 by a uint112, returning a UQ112x112
    function uqdiv(uint224 x, uint112 y) internal pure returns (uint224 z) {
        z = x / uint224(y);
    }
}

// File: contracts/interfaces/IERC20.sol

pragma solidity >=0.5.0;

interface IERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);
}

// File: contracts/interfaces/IUniswapV2Factory.sol

pragma solidity >=0.5.0;

interface IUniswapV2Factory {
    event PairCreated(address indexed token0, address indexed token1, address pair, uint);

    function feeTo() external view returns (address);
    function feeToSetter() external view returns (address);

    function getPair(address tokenA, address tokenB) external view returns (address pair);
    function allPairs(uint) external view returns (address pair);
    function allPairsLength() external view returns (uint);

    function createPair(address tokenA, address tokenB) external returns (address pair);

    function setFeeTo(address) external;
    function setFeeToSetter(address) external;
}

// File: contracts/interfaces/IUniswapV2Callee.sol

pragma solidity >=0.5.0;

interface IUniswapV2Callee {
    function uniswapV2Call(address sender, uint amount0, uint amount1, bytes calldata data) external;
}

// File: contracts/UniswapV2Pair.sol

pragma solidity =0.5.16;








contract UniswapV2Pair is IUniswapV2Pair, UniswapV2ERC20 {
    using SafeMath  for uint;
    using UQ112x112 for uint224;

    uint public constant MINIMUM_LIQUIDITY = 10**3;
    bytes4 private constant SELECTOR = bytes4(keccak256(bytes('transfer(address,uint256)')));

    address public factory;
    address public token0;
    address public token1;

    uint112 private reserve0;           // uses single storage slot, accessible via getReserves
    uint112 private reserve1;           // uses single storage slot, accessible via getReserves
    uint32  private blockTimestampLast; // uses single storage slot, accessible via getReserves

    uint public price0CumulativeLast;
    uint public price1CumulativeLast;
    uint public kLast; // reserve0 * reserve1, as of immediately after the most recent liquidity event

    uint private unlocked = 1;
    modifier lock() {
        require(unlocked == 1, 'UniswapV2: LOCKED');
        unlocked = 0;
        _;
        unlocked = 1;
    }

    function getReserves() public view returns (uint112 _reserve0, uint112 _reserve1, uint32 _blockTimestampLast) {
        _reserve0 = reserve0;
        _reserve1 = reserve1;
        _blockTimestampLast = blockTimestampLast;
    }

    function _safeTransfer(address token, address to, uint value) private {
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(SELECTOR, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'UniswapV2: TRANSFER_FAILED');
    }

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    constructor() public {
        factory = msg.sender;
    }

    // called once by the factory at time of deployment
    function initialize(address _token0, address _token1) external {
        require(msg.sender == factory, 'UniswapV2: FORBIDDEN'); // sufficient check
        token0 = _token0;
        token1 = _token1;
    }

    // update reserves and, on the first call per block, price accumulators
    function _update(uint balance0, uint balance1, uint112 _reserve0, uint112 _reserve1) private {
        require(balance0 <= uint112(-1) && balance1 <= uint112(-1), 'UniswapV2: OVERFLOW');
        uint32 blockTimestamp = uint32(block.timestamp % 2**32);
        uint32 timeElapsed = blockTimestamp - blockTimestampLast; // overflow is desired
        if (timeElapsed > 0 && _reserve0 != 0 && _reserve1 != 0) {
            // * never overflows, and + overflow is desired
            price0CumulativeLast += uint(UQ112x112.encode(_reserve1).uqdiv(_reserve0)) * timeElapsed;
            price1CumulativeLast += uint(UQ112x112.encode(_reserve0).uqdiv(_reserve1)) * timeElapsed;
        }
        reserve0 = uint112(balance0);
        reserve1 = uint112(balance1);
        blockTimestampLast = blockTimestamp;
        emit Sync(reserve0, reserve1);
    }

    // if fee is on, mint liquidity equivalent to 1/6th of the growth in sqrt(k)
    function _mintFee(uint112 _reserve0, uint112 _reserve1) private returns (bool feeOn) {
        address feeTo = IUniswapV2Factory(factory).feeTo();
        feeOn = feeTo != address(0);
        uint _kLast = kLast; // gas savings
        if (feeOn) {
            if (_kLast != 0) {
                uint rootK = Math.sqrt(uint(_reserve0).mul(_reserve1));
                uint rootKLast = Math.sqrt(_kLast);
                if (rootK > rootKLast) {
                    uint numerator = totalSupply.mul(rootK.sub(rootKLast));
                    uint denominator = rootK.mul(5).add(rootKLast);
                    uint liquidity = numerator / denominator;
                    if (liquidity > 0) _mint(feeTo, liquidity);
                }
            }
        } else if (_kLast != 0) {
            kLast = 0;
        }
    }

    // this low-level function should be called from a contract which performs important safety checks
    function mint(address to) external lock returns (uint liquidity) {
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        uint balance0 = IERC20(token0).balanceOf(address(this));
        uint balance1 = IERC20(token1).balanceOf(address(this));
        uint amount0 = balance0.sub(_reserve0);
        uint amount1 = balance1.sub(_reserve1);

        bool feeOn = _mintFee(_reserve0, _reserve1);
        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        if (_totalSupply == 0) {
            liquidity = Math.sqrt(amount0.mul(amount1)).sub(MINIMUM_LIQUIDITY);
           _mint(address(0), MINIMUM_LIQUIDITY); // permanently lock the first MINIMUM_LIQUIDITY tokens
        } else {
            liquidity = Math.min(amount0.mul(_totalSupply) / _reserve0, amount1.mul(_totalSupply) / _reserve1);
        }
        require(liquidity > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_MINTED');
        _mint(to, liquidity);

        _update(balance0, balance1, _reserve0, _reserve1);
        if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
        emit Mint(msg.sender, amount0, amount1);
    }

    // this low-level function should be called from a contract which performs important safety checks
    function burn(address to) external lock returns (uint amount0, uint amount1) {
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        address _token0 = token0;                                // gas savings
        address _token1 = token1;                                // gas savings
        uint balance0 = IERC20(_token0).balanceOf(address(this));
        uint balance1 = IERC20(_token1).balanceOf(address(this));
        uint liquidity = balanceOf[address(this)];

        bool feeOn = _mintFee(_reserve0, _reserve1);
        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        amount0 = liquidity.mul(balance0) / _totalSupply; // using balances ensures pro-rata distribution
        amount1 = liquidity.mul(balance1) / _totalSupply; // using balances ensures pro-rata distribution
        require(amount0 > 0 && amount1 > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_BURNED');
        _burn(address(this), liquidity);
        _safeTransfer(_token0, to, amount0);
        _safeTransfer(_token1, to, amount1);
        balance0 = IERC20(_token0).balanceOf(address(this));
        balance1 = IERC20(_token1).balanceOf(address(this));

        _update(balance0, balance1, _reserve0, _reserve1);
        if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
        emit Burn(msg.sender, amount0, amount1, to);
    }

    // this low-level function should be called from a contract which performs important safety checks
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external lock {
        require(amount0Out > 0 || amount1Out > 0, 'UniswapV2: INSUFFICIENT_OUTPUT_AMOUNT');
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        require(amount0Out < _reserve0 && amount1Out < _reserve1, 'UniswapV2: INSUFFICIENT_LIQUIDITY');

        uint balance0;
        uint balance1;
        { // scope for _token{0,1}, avoids stack too deep errors
        address _token0 = token0;
        address _token1 = token1;
        require(to != _token0 && to != _token1, 'UniswapV2: INVALID_TO');
        if (amount0Out > 0) _safeTransfer(_token0, to, amount0Out); // optimistically transfer tokens
        if (amount1Out > 0) _safeTransfer(_token1, to, amount1Out); // optimistically transfer tokens
        if (data.length > 0) IUniswapV2Callee(to).uniswapV2Call(msg.sender, amount0Out, amount1Out, data);
        balance0 = IERC20(_token0).balanceOf(address(this));
        balance1 = IERC20(_token1).balanceOf(address(this));
        }
        uint amount0In = balance0 > _reserve0 - amount0Out ? balance0 - (_reserve0 - amount0Out) : 0;
        uint amount1In = balance1 > _reserve1 - amount1Out ? balance1 - (_reserve1 - amount1Out) : 0;
        require(amount0In > 0 || amount1In > 0, 'UniswapV2: INSUFFICIENT_INPUT_AMOUNT');
        { // scope for reserve{0,1}Adjusted, avoids stack too deep errors
        uint balance0Adjusted = balance0.mul(1000).sub(amount0In.mul(3));
        uint balance1Adjusted = balance1.mul(1000).sub(amount1In.mul(3));
        require(balance0Adjusted.mul(balance1Adjusted) >= uint(_reserve0).mul(_reserve1).mul(1000**2), 'UniswapV2: K');
        }

        _update(balance0, balance1, _reserve0, _reserve1);
        emit Swap(msg.sender, amount0In, amount1In, amount0Out, amount1Out, to);
    }

    // force balances to match reserves
    function skim(address to) external lock {
        address _token0 = token0; // gas savings
        address _token1 = token1; // gas savings
        _safeTransfer(_token0, to, IERC20(_token0).balanceOf(address(this)).sub(reserve0));
        _safeTransfer(_token1, to, IERC20(_token1).balanceOf(address(this)).sub(reserve1));
    }

    // force reserves to match balances
    function sync() external lock {
        _update(IERC20(token0).balanceOf(address(this)), IERC20(token1).balanceOf(address(this)), reserve0, reserve1);
    }
}

pragma solidity 0.4.24;

// File: openzeppelin-solidity/contracts/token/ERC20/ERC20Basic.sol

/**
 * @title ERC20Basic
 * @dev Simpler version of ERC20 interface
 * See https://github.com/ethereum/EIPs/issues/179
 */
contract ERC20Basic {
  function totalSupply() public view returns (uint256);
  function balanceOf(address _who) public view returns (uint256);
  function transfer(address _to, uint256 _value) public returns (bool);
  event Transfer(address indexed from, address indexed to, uint256 value);
}

// File: openzeppelin-solidity/contracts/math/SafeMath.sol

/**
 * @title SafeMath
 * @dev Math operations with safety checks that throw on error
 */
library SafeMath {

  /**
  * @dev Multiplies two numbers, throws on overflow.
  */
  function mul(uint256 _a, uint256 _b) internal pure returns (uint256 c) {
    // Gas optimization: this is cheaper than asserting 'a' not being zero, but the
    // benefit is lost if 'b' is also tested.
    // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
    if (_a == 0) {
      return 0;
    }

    c = _a * _b;
    assert(c / _a == _b);
    return c;
  }

  /**
  * @dev Integer division of two numbers, truncating the quotient.
  */
  function div(uint256 _a, uint256 _b) internal pure returns (uint256) {
    // assert(_b > 0); // Solidity automatically throws when dividing by 0
    // uint256 c = _a / _b;
    // assert(_a == _b * c + _a % _b); // There is no case in which this doesn't hold
    return _a / _b;
  }

  /**
  * @dev Subtracts two numbers, throws on overflow (i.e. if subtrahend is greater than minuend).
  */
  function sub(uint256 _a, uint256 _b) internal pure returns (uint256) {
    assert(_b <= _a);
    return _a - _b;
  }

  /**
  * @dev Adds two numbers, throws on overflow.
  */
  function add(uint256 _a, uint256 _b) internal pure returns (uint256 c) {
    c = _a + _b;
    assert(c >= _a);
    return c;
  }
}

// File: openzeppelin-solidity/contracts/token/ERC20/BasicToken.sol

/**
 * @title Basic token
 * @dev Basic version of StandardToken, with no allowances.
 */
contract BasicToken is ERC20Basic {
  using SafeMath for uint256;

  mapping(address => uint256) internal balances;

  uint256 internal totalSupply_;

  /**
  * @dev Total number of tokens in existence
  */
  function totalSupply() public view returns (uint256) {
    return totalSupply_;
  }

  /**
  * @dev Transfer token for a specified address
  * @param _to The address to transfer to.
  * @param _value The amount to be transferred.
  */
  function transfer(address _to, uint256 _value) public returns (bool) {
    require(_value <= balances[msg.sender]);
    require(_to != address(0));

    balances[msg.sender] = balances[msg.sender].sub(_value);
    balances[_to] = balances[_to].add(_value);
    emit Transfer(msg.sender, _to, _value);
    return true;
  }

  /**
  * @dev Gets the balance of the specified address.
  * @param _owner The address to query the the balance of.
  * @return An uint256 representing the amount owned by the passed address.
  */
  function balanceOf(address _owner) public view returns (uint256) {
    return balances[_owner];
  }

}

// File: openzeppelin-solidity/contracts/token/ERC20/ERC20.sol

/**
 * @title ERC20 interface
 * @dev see https://github.com/ethereum/EIPs/issues/20
 */
contract ERC20 is ERC20Basic {
  function allowance(address _owner, address _spender)
    public view returns (uint256);

  function transferFrom(address _from, address _to, uint256 _value)
    public returns (bool);

  function approve(address _spender, uint256 _value) public returns (bool);
  event Approval(
    address indexed owner,
    address indexed spender,
    uint256 value
  );
}

// File: openzeppelin-solidity/contracts/token/ERC20/StandardToken.sol

/**
 * @title Standard ERC20 token
 *
 * @dev Implementation of the basic standard token.
 * https://github.com/ethereum/EIPs/issues/20
 * Based on code by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
 */
contract StandardToken is ERC20, BasicToken {

  mapping (address => mapping (address => uint256)) internal allowed;


  /**
   * @dev Transfer tokens from one address to another
   * @param _from address The address which you want to send tokens from
   * @param _to address The address which you want to transfer to
   * @param _value uint256 the amount of tokens to be transferred
   */
  function transferFrom(
    address _from,
    address _to,
    uint256 _value
  )
    public
    returns (bool)
  {
    require(_value <= balances[_from]);
    require(_value <= allowed[_from][msg.sender]);
    require(_to != address(0));

    balances[_from] = balances[_from].sub(_value);
    balances[_to] = balances[_to].add(_value);
    allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
    emit Transfer(_from, _to, _value);
    return true;
  }

  /**
   * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
   * Beware that changing an allowance with this method brings the risk that someone may use both the old
   * and the new allowance by unfortunate transaction ordering. One possible solution to mitigate this
   * race condition is to first reduce the spender's allowance to 0 and set the desired value afterwards:
   * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
   * @param _spender The address which will spend the funds.
   * @param _value The amount of tokens to be spent.
   */
  function approve(address _spender, uint256 _value) public returns (bool) {
    allowed[msg.sender][_spender] = _value;
    emit Approval(msg.sender, _spender, _value);
    return true;
  }

  /**
   * @dev Function to check the amount of tokens that an owner allowed to a spender.
   * @param _owner address The address which owns the funds.
   * @param _spender address The address which will spend the funds.
   * @return A uint256 specifying the amount of tokens still available for the spender.
   */
  function allowance(
    address _owner,
    address _spender
   )
    public
    view
    returns (uint256)
  {
    return allowed[_owner][_spender];
  }

  /**
   * @dev Increase the amount of tokens that an owner allowed to a spender.
   * approve should be called when allowed[_spender] == 0. To increment
   * allowed value is better to use this function to avoid 2 calls (and wait until
   * the first transaction is mined)
   * From MonolithDAO Token.sol
   * @param _spender The address which will spend the funds.
   * @param _addedValue The amount of tokens to increase the allowance by.
   */
  function increaseApproval(
    address _spender,
    uint256 _addedValue
  )
    public
    returns (bool)
  {
    allowed[msg.sender][_spender] = (
      allowed[msg.sender][_spender].add(_addedValue));
    emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
    return true;
  }

  /**
   * @dev Decrease the amount of tokens that an owner allowed to a spender.
   * approve should be called when allowed[_spender] == 0. To decrement
   * allowed value is better to use this function to avoid 2 calls (and wait until
   * the first transaction is mined)
   * From MonolithDAO Token.sol
   * @param _spender The address which will spend the funds.
   * @param _subtractedValue The amount of tokens to decrease the allowance by.
   */
  function decreaseApproval(
    address _spender,
    uint256 _subtractedValue
  )
    public
    returns (bool)
  {
    uint256 oldValue = allowed[msg.sender][_spender];
    if (_subtractedValue >= oldValue) {
      allowed[msg.sender][_spender] = 0;
    } else {
      allowed[msg.sender][_spender] = oldValue.sub(_subtractedValue);
    }
    emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
    return true;
  }

}

// File: openzeppelin-solidity/contracts/token/ERC20/DetailedERC20.sol

/**
 * @title DetailedERC20 token
 * @dev The decimals are only for visualization purposes.
 * All the operations are done using the smallest and indivisible token unit,
 * just as on Ethereum all the operations are done in wei.
 */
contract DetailedERC20 is ERC20 {
  string public name;
  string public symbol;
  uint8 public decimals;

  constructor(string _name, string _symbol, uint8 _decimals) public {
    name = _name;
    symbol = _symbol;
    decimals = _decimals;
  }
}

// File: openzeppelin-solidity/contracts/ownership/Ownable.sol

/**
 * @title Ownable
 * @dev The Ownable contract has an owner address, and provides basic authorization control
 * functions, this simplifies the implementation of "user permissions".
 */
contract Ownable {
  address public owner;


  event OwnershipRenounced(address indexed previousOwner);
  event OwnershipTransferred(
    address indexed previousOwner,
    address indexed newOwner
  );


  /**
   * @dev The Ownable constructor sets the original `owner` of the contract to the sender
   * account.
   */
  constructor() public {
    owner = msg.sender;
  }

  /**
   * @dev Throws if called by any account other than the owner.
   */
  modifier onlyOwner() {
    require(msg.sender == owner);
    _;
  }

  /**
   * @dev Allows the current owner to relinquish control of the contract.
   * @notice Renouncing to ownership will leave the contract without an owner.
   * It will not be possible to call the functions with the `onlyOwner`
   * modifier anymore.
   */
  function renounceOwnership() public onlyOwner {
    emit OwnershipRenounced(owner);
    owner = address(0);
  }

  /**
   * @dev Allows the current owner to transfer control of the contract to a newOwner.
   * @param _newOwner The address to transfer ownership to.
   */
  function transferOwnership(address _newOwner) public onlyOwner {
    _transferOwnership(_newOwner);
  }

  /**
   * @dev Transfers control of the contract to a newOwner.
   * @param _newOwner The address to transfer ownership to.
   */
  function _transferOwnership(address _newOwner) internal {
    require(_newOwner != address(0));
    emit OwnershipTransferred(owner, _newOwner);
    owner = _newOwner;
  }
}

// File: openzeppelin-solidity/contracts/token/ERC20/MintableToken.sol

/**
 * @title Mintable token
 * @dev Simple ERC20 Token example, with mintable token creation
 * Based on code by TokenMarketNet: https://github.com/TokenMarketNet/ico/blob/master/contracts/MintableToken.sol
 */
contract MintableToken is StandardToken, Ownable {
  event Mint(address indexed to, uint256 amount);
  event MintFinished();

  bool public mintingFinished = false;


  modifier canMint() {
    require(!mintingFinished);
    _;
  }

  modifier hasMintPermission() {
    require(msg.sender == owner);
    _;
  }

  /**
   * @dev Function to mint tokens
   * @param _to The address that will receive the minted tokens.
   * @param _amount The amount of tokens to mint.
   * @return A boolean that indicates if the operation was successful.
   */
  function mint(
    address _to,
    uint256 _amount
  )
    public
    hasMintPermission
    canMint
    returns (bool)
  {
    totalSupply_ = totalSupply_.add(_amount);
    balances[_to] = balances[_to].add(_amount);
    emit Mint(_to, _amount);
    emit Transfer(address(0), _to, _amount);
    return true;
  }

  /**
   * @dev Function to stop minting new tokens.
   * @return True if the operation was successful.
   */
  function finishMinting() public onlyOwner canMint returns (bool) {
    mintingFinished = true;
    emit MintFinished();
    return true;
  }
}

// File: openzeppelin-solidity/contracts/token/ERC20/BurnableToken.sol

/**
 * @title Burnable Token
 * @dev Token that can be irreversibly burned (destroyed).
 */
contract BurnableToken is BasicToken {

  event Burn(address indexed burner, uint256 value);

  /**
   * @dev Burns a specific amount of tokens.
   * @param _value The amount of token to be burned.
   */
  function burn(uint256 _value) public {
    _burn(msg.sender, _value);
  }

  function _burn(address _who, uint256 _value) internal {
    require(_value <= balances[_who]);
    // no need to require value <= totalSupply, since that would imply the
    // sender's balance is greater than the totalSupply, which *should* be an assertion failure

    balances[_who] = balances[_who].sub(_value);
    totalSupply_ = totalSupply_.sub(_value);
    emit Burn(_who, _value);
    emit Transfer(_who, address(0), _value);
  }
}

// File: openzeppelin-solidity/contracts/lifecycle/Pausable.sol

/**
 * @title Pausable
 * @dev Base contract which allows children to implement an emergency stop mechanism.
 */
contract Pausable is Ownable {
  event Pause();
  event Unpause();

  bool public paused = false;


  /**
   * @dev Modifier to make a function callable only when the contract is not paused.
   */
  modifier whenNotPaused() {
    require(!paused);
    _;
  }

  /**
   * @dev Modifier to make a function callable only when the contract is paused.
   */
  modifier whenPaused() {
    require(paused);
    _;
  }

  /**
   * @dev called by the owner to pause, triggers stopped state
   */
  function pause() public onlyOwner whenNotPaused {
    paused = true;
    emit Pause();
  }

  /**
   * @dev called by the owner to unpause, returns to normal state
   */
  function unpause() public onlyOwner whenPaused {
    paused = false;
    emit Unpause();
  }
}

// File: openzeppelin-solidity/contracts/token/ERC20/PausableToken.sol

/**
 * @title Pausable token
 * @dev StandardToken modified with pausable transfers.
 **/
contract PausableToken is StandardToken, Pausable {

  function transfer(
    address _to,
    uint256 _value
  )
    public
    whenNotPaused
    returns (bool)
  {
    return super.transfer(_to, _value);
  }

  function transferFrom(
    address _from,
    address _to,
    uint256 _value
  )
    public
    whenNotPaused
    returns (bool)
  {
    return super.transferFrom(_from, _to, _value);
  }

  function approve(
    address _spender,
    uint256 _value
  )
    public
    whenNotPaused
    returns (bool)
  {
    return super.approve(_spender, _value);
  }

  function increaseApproval(
    address _spender,
    uint _addedValue
  )
    public
    whenNotPaused
    returns (bool success)
  {
    return super.increaseApproval(_spender, _addedValue);
  }

  function decreaseApproval(
    address _spender,
    uint _subtractedValue
  )
    public
    whenNotPaused
    returns (bool success)
  {
    return super.decreaseApproval(_spender, _subtractedValue);
  }
}

// File: openzeppelin-solidity/contracts/ownership/Claimable.sol

/**
 * @title Claimable
 * @dev Extension for the Ownable contract, where the ownership needs to be claimed.
 * This allows the new owner to accept the transfer.
 */
contract Claimable is Ownable {
  address public pendingOwner;

  /**
   * @dev Modifier throws if called by any account other than the pendingOwner.
   */
  modifier onlyPendingOwner() {
    require(msg.sender == pendingOwner);
    _;
  }

  /**
   * @dev Allows the current owner to set the pendingOwner address.
   * @param newOwner The address to transfer ownership to.
   */
  function transferOwnership(address newOwner) public onlyOwner {
    pendingOwner = newOwner;
  }

  /**
   * @dev Allows the pendingOwner address to finalize the transfer.
   */
  function claimOwnership() public onlyPendingOwner {
    emit OwnershipTransferred(owner, pendingOwner);
    owner = pendingOwner;
    pendingOwner = address(0);
  }
}

// File: openzeppelin-solidity/contracts/token/ERC20/SafeERC20.sol

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure.
 * To use this library you can add a `using SafeERC20 for ERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
  function safeTransfer(
    ERC20Basic _token,
    address _to,
    uint256 _value
  )
    internal
  {
    require(_token.transfer(_to, _value));
  }

  function safeTransferFrom(
    ERC20 _token,
    address _from,
    address _to,
    uint256 _value
  )
    internal
  {
    require(_token.transferFrom(_from, _to, _value));
  }

  function safeApprove(
    ERC20 _token,
    address _spender,
    uint256 _value
  )
    internal
  {
    require(_token.approve(_spender, _value));
  }
}

// File: openzeppelin-solidity/contracts/ownership/CanReclaimToken.sol

/**
 * @title Contracts that should be able to recover tokens
 * @author SylTi
 * @dev This allow a contract to recover any ERC20 token received in a contract by transferring the balance to the contract owner.
 * This will prevent any accidental loss of tokens.
 */
contract CanReclaimToken is Ownable {
  using SafeERC20 for ERC20Basic;

  /**
   * @dev Reclaim all ERC20Basic compatible tokens
   * @param _token ERC20Basic The address of the token contract
   */
  function reclaimToken(ERC20Basic _token) external onlyOwner {
    uint256 balance = _token.balanceOf(this);
    _token.safeTransfer(owner, balance);
  }

}

// File: contracts/utils/OwnableContract.sol

// empty block is used as this contract just inherits others.
contract OwnableContract is CanReclaimToken, Claimable { } /* solhint-disable-line no-empty-blocks */

// File: contracts/token/WBTC.sol

contract WBTC is StandardToken, DetailedERC20("Wrapped BTC", "WBTC", 8),
    MintableToken, BurnableToken, PausableToken, OwnableContract {

    function burn(uint value) public onlyOwner {
        super.burn(value);
    }

    function finishMinting() public onlyOwner returns (bool) {
        return false;
    }

    function renounceOwnership() public onlyOwner {
        revert("renouncing ownership is blocked");
    }
}

pragma solidity ^0.4.24;
// File: @aragon/apps-shared-minime/contracts/ITokenController.sol
/// @dev The token controller contract must implement these functions


interface ITokenController {
    /// @notice Called when `_owner` sends ether to the MiniMe Token contract
    /// @param _owner The address that sent the ether to create tokens
    /// @return True if the ether is accepted, false if it throws
    function proxyPayment(address _owner) external payable returns(bool);

    /// @notice Notifies the controller about a token transfer allowing the
    ///  controller to react if desired
    /// @param _from The origin of the transfer
    /// @param _to The destination of the transfer
    /// @param _amount The amount of the transfer
    /// @return False if the controller does not authorize the transfer
    function onTransfer(address _from, address _to, uint _amount) external returns(bool);

    /// @notice Notifies the controller about an approval allowing the
    ///  controller to react if desired
    /// @param _owner The address that calls `approve()`
    /// @param _spender The spender in the `approve()` call
    /// @param _amount The amount in the `approve()` call
    /// @return False if the controller does not authorize the approval
    function onApprove(address _owner, address _spender, uint _amount) external returns(bool);
}
// File: @aragon/apps-shared-minime/contracts/MiniMeToken.sol
/*
    Copyright 2016, Jordi Baylina
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/// @title MiniMeToken Contract
/// @author Jordi Baylina
/// @dev This token contract's goal is to make it easy for anyone to clone this
///  token using the token distribution at a given block, this will allow DAO's
///  and DApps to upgrade their features in a decentralized manner without
///  affecting the original token
/// @dev It is ERC20 compliant, but still needs to under go further testing.


contract Controlled {
    /// @notice The address of the controller is the only address that can call
    ///  a function with this modifier
    modifier onlyController {
        require(msg.sender == controller);
        _;
    }

    address public controller;

    function Controlled()  public { controller = msg.sender;}

    /// @notice Changes the controller of the contract
    /// @param _newController The new controller of the contract
    function changeController(address _newController) onlyController  public {
        controller = _newController;
    }
}

contract ApproveAndCallFallBack {
    function receiveApproval(
        address from,
        uint256 _amount,
        address _token,
        bytes _data
    ) public;
}

/// @dev The actual token contract, the default controller is the msg.sender
///  that deploys the contract, so usually this token will be deployed by a
///  token controller contract, which Giveth will call a "Campaign"
contract MiniMeToken is Controlled {

    string public name;                //The Token's name: e.g. DigixDAO Tokens
    uint8 public decimals;             //Number of decimals of the smallest unit
    string public symbol;              //An identifier: e.g. REP
    string public version = "MMT_0.1"; //An arbitrary versioning scheme


    /// @dev `Checkpoint` is the structure that attaches a block number to a
    ///  given value, the block number attached is the one that last changed the
    ///  value
    struct Checkpoint {

        // `fromBlock` is the block number that the value was generated from
        uint128 fromBlock;

        // `value` is the amount of tokens at a specific block number
        uint128 value;
    }

    // `parentToken` is the Token address that was cloned to produce this token;
    //  it will be 0x0 for a token that was not cloned
    MiniMeToken public parentToken;

    // `parentSnapShotBlock` is the block number from the Parent Token that was
    //  used to determine the initial distribution of the Clone Token
    uint public parentSnapShotBlock;

    // `creationBlock` is the block number that the Clone Token was created
    uint public creationBlock;

    // `balances` is the map that tracks the balance of each address, in this
    //  contract when the balance changes the block number that the change
    //  occurred is also included in the map
    mapping (address => Checkpoint[]) balances;

    // `allowed` tracks any extra transfer rights as in all ERC20 tokens
    mapping (address => mapping (address => uint256)) allowed;

    // Tracks the history of the `totalSupply` of the token
    Checkpoint[] totalSupplyHistory;

    // Flag that determines if the token is transferable or not.
    bool public transfersEnabled;

    // The factory used to create new clone tokens
    MiniMeTokenFactory public tokenFactory;

////////////////
// Constructor
////////////////

    /// @notice Constructor to create a MiniMeToken
    /// @param _tokenFactory The address of the MiniMeTokenFactory contract that
    ///  will create the Clone token contracts, the token factory needs to be
    ///  deployed first
    /// @param _parentToken Address of the parent token, set to 0x0 if it is a
    ///  new token
    /// @param _parentSnapShotBlock Block of the parent token that will
    ///  determine the initial distribution of the clone token, set to 0 if it
    ///  is a new token
    /// @param _tokenName Name of the new token
    /// @param _decimalUnits Number of decimals of the new token
    /// @param _tokenSymbol Token Symbol for the new token
    /// @param _transfersEnabled If true, tokens will be able to be transferred
    function MiniMeToken(
        MiniMeTokenFactory _tokenFactory,
        MiniMeToken _parentToken,
        uint _parentSnapShotBlock,
        string _tokenName,
        uint8 _decimalUnits,
        string _tokenSymbol,
        bool _transfersEnabled
    )  public
    {
        tokenFactory = _tokenFactory;
        name = _tokenName;                                 // Set the name
        decimals = _decimalUnits;                          // Set the decimals
        symbol = _tokenSymbol;                             // Set the symbol
        parentToken = _parentToken;
        parentSnapShotBlock = _parentSnapShotBlock;
        transfersEnabled = _transfersEnabled;
        creationBlock = block.number;
    }


///////////////////
// ERC20 Methods
///////////////////

    /// @notice Send `_amount` tokens to `_to` from `msg.sender`
    /// @param _to The address of the recipient
    /// @param _amount The amount of tokens to be transferred
    /// @return Whether the transfer was successful or not
    function transfer(address _to, uint256 _amount) public returns (bool success) {
        require(transfersEnabled);
        return doTransfer(msg.sender, _to, _amount);
    }

    /// @notice Send `_amount` tokens to `_to` from `_from` on the condition it
    ///  is approved by `_from`
    /// @param _from The address holding the tokens being transferred
    /// @param _to The address of the recipient
    /// @param _amount The amount of tokens to be transferred
    /// @return True if the transfer was successful
    function transferFrom(address _from, address _to, uint256 _amount) public returns (bool success) {

        // The controller of this contract can move tokens around at will,
        //  this is important to recognize! Confirm that you trust the
        //  controller of this contract, which in most situations should be
        //  another open source smart contract or 0x0
        if (msg.sender != controller) {
            require(transfersEnabled);

            // The standard ERC 20 transferFrom functionality
            if (allowed[_from][msg.sender] < _amount)
                return false;
            allowed[_from][msg.sender] -= _amount;
        }
        return doTransfer(_from, _to, _amount);
    }

    /// @dev This is the actual transfer function in the token contract, it can
    ///  only be called by other functions in this contract.
    /// @param _from The address holding the tokens being transferred
    /// @param _to The address of the recipient
    /// @param _amount The amount of tokens to be transferred
    /// @return True if the transfer was successful
    function doTransfer(address _from, address _to, uint _amount) internal returns(bool) {
        if (_amount == 0) {
            return true;
        }
        require(parentSnapShotBlock < block.number);
        // Do not allow transfer to 0x0 or the token contract itself
        require((_to != 0) && (_to != address(this)));
        // If the amount being transfered is more than the balance of the
        //  account the transfer returns false
        var previousBalanceFrom = balanceOfAt(_from, block.number);
        if (previousBalanceFrom < _amount) {
            return false;
        }
        // Alerts the token controller of the transfer
        if (isContract(controller)) {
            // Adding the ` == true` makes the linter shut up so...
            require(ITokenController(controller).onTransfer(_from, _to, _amount) == true);
        }
        // First update the balance array with the new value for the address
        //  sending the tokens
        updateValueAtNow(balances[_from], previousBalanceFrom - _amount);
        // Then update the balance array with the new value for the address
        //  receiving the tokens
        var previousBalanceTo = balanceOfAt(_to, block.number);
        require(previousBalanceTo + _amount >= previousBalanceTo); // Check for overflow
        updateValueAtNow(balances[_to], previousBalanceTo + _amount);
        // An event to make the transfer easy to find on the blockchain
        Transfer(_from, _to, _amount);
        return true;
    }

    /// @param _owner The address that's balance is being requested
    /// @return The balance of `_owner` at the current block
    function balanceOf(address _owner) public constant returns (uint256 balance) {
        return balanceOfAt(_owner, block.number);
    }

    /// @notice `msg.sender` approves `_spender` to spend `_amount` tokens on
    ///  its behalf. This is a modified version of the ERC20 approve function
    ///  to be a little bit safer
    /// @param _spender The address of the account able to transfer the tokens
    /// @param _amount The amount of tokens to be approved for transfer
    /// @return True if the approval was successful
    function approve(address _spender, uint256 _amount) public returns (bool success) {
        require(transfersEnabled);

        // To change the approve amount you first have to reduce the addresses`
        //  allowance to zero by calling `approve(_spender,0)` if it is not
        //  already 0 to mitigate the race condition described here:
        //  https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
        require((_amount == 0) || (allowed[msg.sender][_spender] == 0));

        // Alerts the token controller of the approve function call
        if (isContract(controller)) {
            // Adding the ` == true` makes the linter shut up so...
            require(ITokenController(controller).onApprove(msg.sender, _spender, _amount) == true);
        }

        allowed[msg.sender][_spender] = _amount;
        Approval(msg.sender, _spender, _amount);
        return true;
    }

    /// @dev This function makes it easy to read the `allowed[]` map
    /// @param _owner The address of the account that owns the token
    /// @param _spender The address of the account able to transfer the tokens
    /// @return Amount of remaining tokens of _owner that _spender is allowed
    ///  to spend
    function allowance(address _owner, address _spender) public constant returns (uint256 remaining) {
        return allowed[_owner][_spender];
    }

    /// @notice `msg.sender` approves `_spender` to send `_amount` tokens on
    ///  its behalf, and then a function is triggered in the contract that is
    ///  being approved, `_spender`. This allows users to use their tokens to
    ///  interact with contracts in one function call instead of two
    /// @param _spender The address of the contract able to transfer the tokens
    /// @param _amount The amount of tokens to be approved for transfer
    /// @return True if the function call was successful
    function approveAndCall(ApproveAndCallFallBack _spender, uint256 _amount, bytes _extraData) public returns (bool success) {
        require(approve(_spender, _amount));

        _spender.receiveApproval(
            msg.sender,
            _amount,
            this,
            _extraData
        );

        return true;
    }

    /// @dev This function makes it easy to get the total number of tokens
    /// @return The total number of tokens
    function totalSupply() public constant returns (uint) {
        return totalSupplyAt(block.number);
    }


////////////////
// Query balance and totalSupply in History
////////////////

    /// @dev Queries the balance of `_owner` at a specific `_blockNumber`
    /// @param _owner The address from which the balance will be retrieved
    /// @param _blockNumber The block number when the balance is queried
    /// @return The balance at `_blockNumber`
    function balanceOfAt(address _owner, uint _blockNumber) public constant returns (uint) {

        // These next few lines are used when the balance of the token is
        //  requested before a check point was ever created for this token, it
        //  requires that the `parentToken.balanceOfAt` be queried at the
        //  genesis block for that token as this contains initial balance of
        //  this token
        if ((balances[_owner].length == 0) || (balances[_owner][0].fromBlock > _blockNumber)) {
            if (address(parentToken) != 0) {
                return parentToken.balanceOfAt(_owner, min(_blockNumber, parentSnapShotBlock));
            } else {
                // Has no parent
                return 0;
            }

        // This will return the expected balance during normal situations
        } else {
            return getValueAt(balances[_owner], _blockNumber);
        }
    }

    /// @notice Total amount of tokens at a specific `_blockNumber`.
    /// @param _blockNumber The block number when the totalSupply is queried
    /// @return The total amount of tokens at `_blockNumber`
    function totalSupplyAt(uint _blockNumber) public constant returns(uint) {

        // These next few lines are used when the totalSupply of the token is
        //  requested before a check point was ever created for this token, it
        //  requires that the `parentToken.totalSupplyAt` be queried at the
        //  genesis block for this token as that contains totalSupply of this
        //  token at this block number.
        if ((totalSupplyHistory.length == 0) || (totalSupplyHistory[0].fromBlock > _blockNumber)) {
            if (address(parentToken) != 0) {
                return parentToken.totalSupplyAt(min(_blockNumber, parentSnapShotBlock));
            } else {
                return 0;
            }

        // This will return the expected totalSupply during normal situations
        } else {
            return getValueAt(totalSupplyHistory, _blockNumber);
        }
    }

////////////////
// Clone Token Method
////////////////

    /// @notice Creates a new clone token with the initial distribution being
    ///  this token at `_snapshotBlock`
    /// @param _cloneTokenName Name of the clone token
    /// @param _cloneDecimalUnits Number of decimals of the smallest unit
    /// @param _cloneTokenSymbol Symbol of the clone token
    /// @param _snapshotBlock Block when the distribution of the parent token is
    ///  copied to set the initial distribution of the new clone token;
    ///  if the block is zero than the actual block, the current block is used
    /// @param _transfersEnabled True if transfers are allowed in the clone
    /// @return The address of the new MiniMeToken Contract
    function createCloneToken(
        string _cloneTokenName,
        uint8 _cloneDecimalUnits,
        string _cloneTokenSymbol,
        uint _snapshotBlock,
        bool _transfersEnabled
    ) public returns(MiniMeToken)
    {
        uint256 snapshot = _snapshotBlock == 0 ? block.number - 1 : _snapshotBlock;

        MiniMeToken cloneToken = tokenFactory.createCloneToken(
            this,
            snapshot,
            _cloneTokenName,
            _cloneDecimalUnits,
            _cloneTokenSymbol,
            _transfersEnabled
        );

        cloneToken.changeController(msg.sender);

        // An event to make the token easy to find on the blockchain
        NewCloneToken(address(cloneToken), snapshot);
        return cloneToken;
    }

////////////////
// Generate and destroy tokens
////////////////

    /// @notice Generates `_amount` tokens that are assigned to `_owner`
    /// @param _owner The address that will be assigned the new tokens
    /// @param _amount The quantity of tokens generated
    /// @return True if the tokens are generated correctly
    function generateTokens(address _owner, uint _amount) onlyController public returns (bool) {
        uint curTotalSupply = totalSupply();
        require(curTotalSupply + _amount >= curTotalSupply); // Check for overflow
        uint previousBalanceTo = balanceOf(_owner);
        require(previousBalanceTo + _amount >= previousBalanceTo); // Check for overflow
        updateValueAtNow(totalSupplyHistory, curTotalSupply + _amount);
        updateValueAtNow(balances[_owner], previousBalanceTo + _amount);
        Transfer(0, _owner, _amount);
        return true;
    }


    /// @notice Burns `_amount` tokens from `_owner`
    /// @param _owner The address that will lose the tokens
    /// @param _amount The quantity of tokens to burn
    /// @return True if the tokens are burned correctly
    function destroyTokens(address _owner, uint _amount) onlyController public returns (bool) {
        uint curTotalSupply = totalSupply();
        require(curTotalSupply >= _amount);
        uint previousBalanceFrom = balanceOf(_owner);
        require(previousBalanceFrom >= _amount);
        updateValueAtNow(totalSupplyHistory, curTotalSupply - _amount);
        updateValueAtNow(balances[_owner], previousBalanceFrom - _amount);
        Transfer(_owner, 0, _amount);
        return true;
    }

////////////////
// Enable tokens transfers
////////////////


    /// @notice Enables token holders to transfer their tokens freely if true
    /// @param _transfersEnabled True if transfers are allowed in the clone
    function enableTransfers(bool _transfersEnabled) onlyController public {
        transfersEnabled = _transfersEnabled;
    }

////////////////
// Internal helper functions to query and set a value in a snapshot array
////////////////

    /// @dev `getValueAt` retrieves the number of tokens at a given block number
    /// @param checkpoints The history of values being queried
    /// @param _block The block number to retrieve the value at
    /// @return The number of tokens being queried
    function getValueAt(Checkpoint[] storage checkpoints, uint _block) constant internal returns (uint) {
        if (checkpoints.length == 0)
            return 0;

        // Shortcut for the actual value
        if (_block >= checkpoints[checkpoints.length-1].fromBlock)
            return checkpoints[checkpoints.length-1].value;
        if (_block < checkpoints[0].fromBlock)
            return 0;

        // Binary search of the value in the array
        uint min = 0;
        uint max = checkpoints.length-1;
        while (max > min) {
            uint mid = (max + min + 1) / 2;
            if (checkpoints[mid].fromBlock<=_block) {
                min = mid;
            } else {
                max = mid-1;
            }
        }
        return checkpoints[min].value;
    }

    /// @dev `updateValueAtNow` used to update the `balances` map and the
    ///  `totalSupplyHistory`
    /// @param checkpoints The history of data being updated
    /// @param _value The new number of tokens
    function updateValueAtNow(Checkpoint[] storage checkpoints, uint _value) internal {
        if ((checkpoints.length == 0) || (checkpoints[checkpoints.length - 1].fromBlock < block.number)) {
            Checkpoint storage newCheckPoint = checkpoints[checkpoints.length++];
            newCheckPoint.fromBlock = uint128(block.number);
            newCheckPoint.value = uint128(_value);
        } else {
            Checkpoint storage oldCheckPoint = checkpoints[checkpoints.length - 1];
            oldCheckPoint.value = uint128(_value);
        }
    }

    /// @dev Internal function to determine if an address is a contract
    /// @param _addr The address being queried
    /// @return True if `_addr` is a contract
    function isContract(address _addr) constant internal returns(bool) {
        uint size;
        if (_addr == 0)
            return false;

        assembly {
            size := extcodesize(_addr)
        }

        return size>0;
    }

    /// @dev Helper function to return a min betwen the two uints
    function min(uint a, uint b) pure internal returns (uint) {
        return a < b ? a : b;
    }

    /// @notice The fallback function: If the contract's controller has not been
    ///  set to 0, then the `proxyPayment` method is called which relays the
    ///  ether and creates tokens as described in the token controller contract
    function () external payable {
        require(isContract(controller));
        // Adding the ` == true` makes the linter shut up so...
        require(ITokenController(controller).proxyPayment.value(msg.value)(msg.sender) == true);
    }

//////////
// Safety Methods
//////////

    /// @notice This method can be used by the controller to extract mistakenly
    ///  sent tokens to this contract.
    /// @param _token The address of the token contract that you want to recover
    ///  set to 0 in case you want to extract ether.
    function claimTokens(address _token) onlyController public {
        if (_token == 0x0) {
            controller.transfer(this.balance);
            return;
        }

        MiniMeToken token = MiniMeToken(_token);
        uint balance = token.balanceOf(this);
        token.transfer(controller, balance);
        ClaimedTokens(_token, controller, balance);
    }

////////////////
// Events
////////////////
    event ClaimedTokens(address indexed _token, address indexed _controller, uint _amount);
    event Transfer(address indexed _from, address indexed _to, uint256 _amount);
    event NewCloneToken(address indexed _cloneToken, uint _snapshotBlock);
    event Approval(
        address indexed _owner,
        address indexed _spender,
        uint256 _amount
        );

}


////////////////
// MiniMeTokenFactory
////////////////

/// @dev This contract is used to generate clone contracts from a contract.
///  In solidity this is the way to create a contract from a contract of the
///  same class
contract MiniMeTokenFactory {

    /// @notice Update the DApp by creating a new token with new functionalities
    ///  the msg.sender becomes the controller of this clone token
    /// @param _parentToken Address of the token being cloned
    /// @param _snapshotBlock Block of the parent token that will
    ///  determine the initial distribution of the clone token
    /// @param _tokenName Name of the new token
    /// @param _decimalUnits Number of decimals of the new token
    /// @param _tokenSymbol Token Symbol for the new token
    /// @param _transfersEnabled If true, tokens will be able to be transferred
    /// @return The address of the new token contract
    function createCloneToken(
        MiniMeToken _parentToken,
        uint _snapshotBlock,
        string _tokenName,
        uint8 _decimalUnits,
        string _tokenSymbol,
        bool _transfersEnabled
    ) public returns (MiniMeToken)
    {
        MiniMeToken newToken = new MiniMeToken(
            this,
            _parentToken,
            _snapshotBlock,
            _tokenName,
            _decimalUnits,
            _tokenSymbol,
            _transfersEnabled
        );

        newToken.changeController(msg.sender);
        return newToken;
    }
}

// File: contracts/common/UnstructuredStorage.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


library UnstructuredStorage {
    function getStorageBool(bytes32 position) internal view returns (bool data) {
        assembly { data := sload(position) }
    }

    function getStorageAddress(bytes32 position) internal view returns (address data) {
        assembly { data := sload(position) }
    }

    function getStorageBytes32(bytes32 position) internal view returns (bytes32 data) {
        assembly { data := sload(position) }
    }

    function getStorageUint256(bytes32 position) internal view returns (uint256 data) {
        assembly { data := sload(position) }
    }

    function setStorageBool(bytes32 position, bool data) internal {
        assembly { sstore(position, data) }
    }

    function setStorageAddress(bytes32 position, address data) internal {
        assembly { sstore(position, data) }
    }

    function setStorageBytes32(bytes32 position, bytes32 data) internal {
        assembly { sstore(position, data) }
    }

    function setStorageUint256(bytes32 position, uint256 data) internal {
        assembly { sstore(position, data) }
    }
}

// File: contracts/acl/IACL.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


interface IACL {
    function initialize(address permissionsCreator) external;

    // TODO: this should be external
    // See https://github.com/ethereum/solidity/issues/4832
    function hasPermission(address who, address where, bytes32 what, bytes how) public view returns (bool);
}

// File: contracts/common/IVaultRecoverable.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


interface IVaultRecoverable {
    event RecoverToVault(address indexed vault, address indexed token, uint256 amount);

    function transferToVault(address token) external;

    function allowRecoverability(address token) external view returns (bool);
    function getRecoveryVault() external view returns (address);
}

// File: contracts/kernel/IKernel.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;




interface IKernelEvents {
    event SetApp(bytes32 indexed namespace, bytes32 indexed appId, address app);
}


// This should be an interface, but interfaces can't inherit yet :(
contract IKernel is IKernelEvents, IVaultRecoverable {
    function acl() public view returns (IACL);
    function hasPermission(address who, address where, bytes32 what, bytes how) public view returns (bool);

    function setApp(bytes32 namespace, bytes32 appId, address app) public;
    function getApp(bytes32 namespace, bytes32 appId) public view returns (address);
}

// File: contracts/apps/AppStorage.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;




contract AppStorage {
    using UnstructuredStorage for bytes32;

    /* Hardcoded constants to save gas
    bytes32 internal constant KERNEL_POSITION = keccak256("aragonOS.appStorage.kernel");
    bytes32 internal constant APP_ID_POSITION = keccak256("aragonOS.appStorage.appId");
    */
    bytes32 internal constant KERNEL_POSITION = 0x4172f0f7d2289153072b0a6ca36959e0cbe2efc3afe50fc81636caa96338137b;
    bytes32 internal constant APP_ID_POSITION = 0xd625496217aa6a3453eecb9c3489dc5a53e6c67b444329ea2b2cbc9ff547639b;

    function kernel() public view returns (IKernel) {
        return IKernel(KERNEL_POSITION.getStorageAddress());
    }

    function appId() public view returns (bytes32) {
        return APP_ID_POSITION.getStorageBytes32();
    }

    function setKernel(IKernel _kernel) internal {
        KERNEL_POSITION.setStorageAddress(address(_kernel));
    }

    function setAppId(bytes32 _appId) internal {
        APP_ID_POSITION.setStorageBytes32(_appId);
    }
}

// File: contracts/common/IsContract.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


contract IsContract {
    /*
    * NOTE: this should NEVER be used for authentication
    * (see pitfalls: https://github.com/fergarrui/ethereum-security/tree/master/contracts/extcodesize).
    *
    * This is only intended to be used as a sanity check that an address is actually a contract,
    * RATHER THAN an address not being a contract.
    */
    function isContract(address _target) internal view returns (bool) {
        if (_target == address(0)) {
            return false;
        }

        uint256 size;
        assembly { size := extcodesize(_target) }
        return size > 0;
    }
}

// File: contracts/lib/misc/ERCProxy.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


contract ERCProxy {
    uint256 internal constant FORWARDING = 1;
    uint256 internal constant UPGRADEABLE = 2;

    function proxyType() public pure returns (uint256 proxyTypeId);
    function implementation() public view returns (address codeAddr);
}

// File: contracts/common/DelegateProxy.sol

pragma solidity 0.4.24;




contract DelegateProxy is ERCProxy, IsContract {
    uint256 internal constant FWD_GAS_LIMIT = 10000;

    /**
    * @dev Performs a delegatecall and returns whatever the delegatecall returned (entire context execution will return!)
    * @param _dst Destination address to perform the delegatecall
    * @param _calldata Calldata for the delegatecall
    */
    function delegatedFwd(address _dst, bytes _calldata) internal {
        require(isContract(_dst));
        uint256 fwdGasLimit = FWD_GAS_LIMIT;

        assembly {
            let result := delegatecall(sub(gas, fwdGasLimit), _dst, add(_calldata, 0x20), mload(_calldata), 0, 0)
            let size := returndatasize
            let ptr := mload(0x40)
            returndatacopy(ptr, 0, size)

            // revert instead of invalid() bc if the underlying call failed with invalid() it already wasted gas.
            // if the call returned error data, forward it
            switch result case 0 { revert(ptr, size) }
            default { return(ptr, size) }
        }
    }
}

// File: contracts/common/DepositableStorage.sol

pragma solidity 0.4.24;



contract DepositableStorage {
    using UnstructuredStorage for bytes32;

    // keccak256("aragonOS.depositableStorage.depositable")
    bytes32 internal constant DEPOSITABLE_POSITION = 0x665fd576fbbe6f247aff98f5c94a561e3f71ec2d3c988d56f12d342396c50cea;

    function isDepositable() public view returns (bool) {
        return DEPOSITABLE_POSITION.getStorageBool();
    }

    function setDepositable(bool _depositable) internal {
        DEPOSITABLE_POSITION.setStorageBool(_depositable);
    }
}

// File: contracts/common/DepositableDelegateProxy.sol

pragma solidity 0.4.24;




contract DepositableDelegateProxy is DepositableStorage, DelegateProxy {
    event ProxyDeposit(address sender, uint256 value);

    function () external payable {
        uint256 forwardGasThreshold = FWD_GAS_LIMIT;
        bytes32 isDepositablePosition = DEPOSITABLE_POSITION;

        // Optimized assembly implementation to prevent EIP-1884 from breaking deposits, reference code in Solidity:
        // https://github.com/aragon/aragonOS/blob/v4.2.1/contracts/common/DepositableDelegateProxy.sol#L10-L20
        assembly {
            // Continue only if the gas left is lower than the threshold for forwarding to the implementation code,
            // otherwise continue outside of the assembly block.
            if lt(gas, forwardGasThreshold) {
                // Only accept the deposit and emit an event if all of the following are true:
                // the proxy accepts deposits (isDepositable), msg.data.length == 0, and msg.value > 0
                if and(and(sload(isDepositablePosition), iszero(calldatasize)), gt(callvalue, 0)) {
                    // Equivalent Solidity code for emitting the event:
                    // emit ProxyDeposit(msg.sender, msg.value);

                    let logData := mload(0x40) // free memory pointer
                    mstore(logData, caller) // add 'msg.sender' to the log data (first event param)
                    mstore(add(logData, 0x20), callvalue) // add 'msg.value' to the log data (second event param)

                    // Emit an event with one topic to identify the event: keccak256('ProxyDeposit(address,uint256)') = 0x15ee...dee1
                    log1(logData, 0x40, 0x15eeaa57c7bd188c1388020bcadc2c436ec60d647d36ef5b9eb3c742217ddee1)

                    stop() // Stop. Exits execution context
                }

                // If any of above checks failed, revert the execution (if ETH was sent, it is returned to the sender)
                revert(0, 0)
            }
        }

        address target = implementation();
        delegatedFwd(target, msg.data);
    }
}

// File: contracts/kernel/KernelConstants.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


contract KernelAppIds {
    /* Hardcoded constants to save gas
    bytes32 internal constant KERNEL_CORE_APP_ID = apmNamehash("kernel");
    bytes32 internal constant KERNEL_DEFAULT_ACL_APP_ID = apmNamehash("acl");
    bytes32 internal constant KERNEL_DEFAULT_VAULT_APP_ID = apmNamehash("vault");
    */
    bytes32 internal constant KERNEL_CORE_APP_ID = 0x3b4bf6bf3ad5000ecf0f989d5befde585c6860fea3e574a4fab4c49d1c177d9c;
    bytes32 internal constant KERNEL_DEFAULT_ACL_APP_ID = 0xe3262375f45a6e2026b7e7b18c2b807434f2508fe1a2a3dfb493c7df8f4aad6a;
    bytes32 internal constant KERNEL_DEFAULT_VAULT_APP_ID = 0x7e852e0fcfce6551c13800f1e7476f982525c2b5277ba14b24339c68416336d1;
}


contract KernelNamespaceConstants {
    /* Hardcoded constants to save gas
    bytes32 internal constant KERNEL_CORE_NAMESPACE = keccak256("core");
    bytes32 internal constant KERNEL_APP_BASES_NAMESPACE = keccak256("base");
    bytes32 internal constant KERNEL_APP_ADDR_NAMESPACE = keccak256("app");
    */
    bytes32 internal constant KERNEL_CORE_NAMESPACE = 0xc681a85306374a5ab27f0bbc385296a54bcd314a1948b6cf61c4ea1bc44bb9f8;
    bytes32 internal constant KERNEL_APP_BASES_NAMESPACE = 0xf1f3eb40f5bc1ad1344716ced8b8a0431d840b5783aea1fd01786bc26f35ac0f;
    bytes32 internal constant KERNEL_APP_ADDR_NAMESPACE = 0xd6f028ca0e8edb4a8c9757ca4fdccab25fa1e0317da1188108f7d2dee14902fb;
}

// File: contracts/apps/AppProxyBase.sol

pragma solidity 0.4.24;






contract AppProxyBase is AppStorage, DepositableDelegateProxy, KernelNamespaceConstants {
    /**
    * @dev Initialize AppProxy
    * @param _kernel Reference to organization kernel for the app
    * @param _appId Identifier for app
    * @param _initializePayload Payload for call to be made after setup to initialize
    */
    constructor(IKernel _kernel, bytes32 _appId, bytes _initializePayload) public {
        setKernel(_kernel);
        setAppId(_appId);

        // Implicit check that kernel is actually a Kernel
        // The EVM doesn't actually provide a way for us to make sure, but we can force a revert to
        // occur if the kernel is set to 0x0 or a non-code address when we try to call a method on
        // it.
        address appCode = getAppBase(_appId);

        // If initialize payload is provided, it will be executed
        if (_initializePayload.length > 0) {
            require(isContract(appCode));
            // Cannot make delegatecall as a delegateproxy.delegatedFwd as it
            // returns ending execution context and halts contract deployment
            require(appCode.delegatecall(_initializePayload));
        }
    }

    function getAppBase(bytes32 _appId) internal view returns (address) {
        return kernel().getApp(KERNEL_APP_BASES_NAMESPACE, _appId);
    }
}

// File: contracts/apps/AppProxyUpgradeable.sol

pragma solidity 0.4.24;



contract AppProxyUpgradeable is AppProxyBase {
    /**
    * @dev Initialize AppProxyUpgradeable (makes it an upgradeable Aragon app)
    * @param _kernel Reference to organization kernel for the app
    * @param _appId Identifier for app
    * @param _initializePayload Payload for call to be made after setup to initialize
    */
    constructor(IKernel _kernel, bytes32 _appId, bytes _initializePayload)
        AppProxyBase(_kernel, _appId, _initializePayload)
        public // solium-disable-line visibility-first
    {
        // solium-disable-previous-line no-empty-blocks
    }

    /**
     * @dev ERC897, the address the proxy would delegate calls to
     */
    function implementation() public view returns (address) {
        return getAppBase(appId());
    }

    /**
     * @dev ERC897, whether it is a forwarding (1) or an upgradeable (2) proxy
     */
    function proxyType() public pure returns (uint256 proxyTypeId) {
        return UPGRADEABLE;
    }
}

// File: contracts/acl/IACL.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


interface IACL {
    function initialize(address permissionsCreator) external;

    // TODO: this should be external
    // See https://github.com/ethereum/solidity/issues/4832
    function hasPermission(address who, address where, bytes32 what, bytes how) public view returns (bool);
}

// File: contracts/common/IVaultRecoverable.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


interface IVaultRecoverable {
    event RecoverToVault(address indexed vault, address indexed token, uint256 amount);

    function transferToVault(address token) external;

    function allowRecoverability(address token) external view returns (bool);
    function getRecoveryVault() external view returns (address);
}

// File: contracts/kernel/IKernel.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;




interface IKernelEvents {
    event SetApp(bytes32 indexed namespace, bytes32 indexed appId, address app);
}


// This should be an interface, but interfaces can't inherit yet :(
contract IKernel is IKernelEvents, IVaultRecoverable {
    function acl() public view returns (IACL);
    function hasPermission(address who, address where, bytes32 what, bytes how) public view returns (bool);

    function setApp(bytes32 namespace, bytes32 appId, address app) public;
    function getApp(bytes32 namespace, bytes32 appId) public view returns (address);
}

// File: contracts/kernel/KernelConstants.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


contract KernelAppIds {
    /* Hardcoded constants to save gas
    bytes32 internal constant KERNEL_CORE_APP_ID = apmNamehash("kernel");
    bytes32 internal constant KERNEL_DEFAULT_ACL_APP_ID = apmNamehash("acl");
    bytes32 internal constant KERNEL_DEFAULT_VAULT_APP_ID = apmNamehash("vault");
    */
    bytes32 internal constant KERNEL_CORE_APP_ID = 0x3b4bf6bf3ad5000ecf0f989d5befde585c6860fea3e574a4fab4c49d1c177d9c;
    bytes32 internal constant KERNEL_DEFAULT_ACL_APP_ID = 0xe3262375f45a6e2026b7e7b18c2b807434f2508fe1a2a3dfb493c7df8f4aad6a;
    bytes32 internal constant KERNEL_DEFAULT_VAULT_APP_ID = 0x7e852e0fcfce6551c13800f1e7476f982525c2b5277ba14b24339c68416336d1;
}


contract KernelNamespaceConstants {
    /* Hardcoded constants to save gas
    bytes32 internal constant KERNEL_CORE_NAMESPACE = keccak256("core");
    bytes32 internal constant KERNEL_APP_BASES_NAMESPACE = keccak256("base");
    bytes32 internal constant KERNEL_APP_ADDR_NAMESPACE = keccak256("app");
    */
    bytes32 internal constant KERNEL_CORE_NAMESPACE = 0xc681a85306374a5ab27f0bbc385296a54bcd314a1948b6cf61c4ea1bc44bb9f8;
    bytes32 internal constant KERNEL_APP_BASES_NAMESPACE = 0xf1f3eb40f5bc1ad1344716ced8b8a0431d840b5783aea1fd01786bc26f35ac0f;
    bytes32 internal constant KERNEL_APP_ADDR_NAMESPACE = 0xd6f028ca0e8edb4a8c9757ca4fdccab25fa1e0317da1188108f7d2dee14902fb;
}

// File: contracts/kernel/KernelStorage.sol

pragma solidity 0.4.24;


contract KernelStorage {
    // namespace => app id => address
    mapping (bytes32 => mapping (bytes32 => address)) public apps;
    bytes32 public recoveryVaultAppId;
}

// File: contracts/common/IsContract.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


contract IsContract {
    /*
    * NOTE: this should NEVER be used for authentication
    * (see pitfalls: https://github.com/fergarrui/ethereum-security/tree/master/contracts/extcodesize).
    *
    * This is only intended to be used as a sanity check that an address is actually a contract,
    * RATHER THAN an address not being a contract.
    */
    function isContract(address _target) internal view returns (bool) {
        if (_target == address(0)) {
            return false;
        }

        uint256 size;
        assembly { size := extcodesize(_target) }
        return size > 0;
    }
}

// File: contracts/lib/misc/ERCProxy.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


contract ERCProxy {
    uint256 internal constant FORWARDING = 1;
    uint256 internal constant UPGRADEABLE = 2;

    function proxyType() public pure returns (uint256 proxyTypeId);
    function implementation() public view returns (address codeAddr);
}

// File: contracts/common/DelegateProxy.sol

pragma solidity 0.4.24;




contract DelegateProxy is ERCProxy, IsContract {
    uint256 internal constant FWD_GAS_LIMIT = 10000;

    /**
    * @dev Performs a delegatecall and returns whatever the delegatecall returned (entire context execution will return!)
    * @param _dst Destination address to perform the delegatecall
    * @param _calldata Calldata for the delegatecall
    */
    function delegatedFwd(address _dst, bytes _calldata) internal {
        require(isContract(_dst));
        uint256 fwdGasLimit = FWD_GAS_LIMIT;

        assembly {
            let result := delegatecall(sub(gas, fwdGasLimit), _dst, add(_calldata, 0x20), mload(_calldata), 0, 0)
            let size := returndatasize
            let ptr := mload(0x40)
            returndatacopy(ptr, 0, size)

            // revert instead of invalid() bc if the underlying call failed with invalid() it already wasted gas.
            // if the call returned error data, forward it
            switch result case 0 { revert(ptr, size) }
            default { return(ptr, size) }
        }
    }
}

// File: contracts/common/UnstructuredStorage.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


library UnstructuredStorage {
    function getStorageBool(bytes32 position) internal view returns (bool data) {
        assembly { data := sload(position) }
    }

    function getStorageAddress(bytes32 position) internal view returns (address data) {
        assembly { data := sload(position) }
    }

    function getStorageBytes32(bytes32 position) internal view returns (bytes32 data) {
        assembly { data := sload(position) }
    }

    function getStorageUint256(bytes32 position) internal view returns (uint256 data) {
        assembly { data := sload(position) }
    }

    function setStorageBool(bytes32 position, bool data) internal {
        assembly { sstore(position, data) }
    }

    function setStorageAddress(bytes32 position, address data) internal {
        assembly { sstore(position, data) }
    }

    function setStorageBytes32(bytes32 position, bytes32 data) internal {
        assembly { sstore(position, data) }
    }

    function setStorageUint256(bytes32 position, uint256 data) internal {
        assembly { sstore(position, data) }
    }
}

// File: contracts/common/DepositableStorage.sol

pragma solidity 0.4.24;



contract DepositableStorage {
    using UnstructuredStorage for bytes32;

    // keccak256("aragonOS.depositableStorage.depositable")
    bytes32 internal constant DEPOSITABLE_POSITION = 0x665fd576fbbe6f247aff98f5c94a561e3f71ec2d3c988d56f12d342396c50cea;

    function isDepositable() public view returns (bool) {
        return DEPOSITABLE_POSITION.getStorageBool();
    }

    function setDepositable(bool _depositable) internal {
        DEPOSITABLE_POSITION.setStorageBool(_depositable);
    }
}

// File: contracts/common/DepositableDelegateProxy.sol

pragma solidity 0.4.24;




contract DepositableDelegateProxy is DepositableStorage, DelegateProxy {
    event ProxyDeposit(address sender, uint256 value);

    function () external payable {
        uint256 forwardGasThreshold = FWD_GAS_LIMIT;
        bytes32 isDepositablePosition = DEPOSITABLE_POSITION;

        // Optimized assembly implementation to prevent EIP-1884 from breaking deposits, reference code in Solidity:
        // https://github.com/aragon/aragonOS/blob/v4.2.1/contracts/common/DepositableDelegateProxy.sol#L10-L20
        assembly {
            // Continue only if the gas left is lower than the threshold for forwarding to the implementation code,
            // otherwise continue outside of the assembly block.
            if lt(gas, forwardGasThreshold) {
                // Only accept the deposit and emit an event if all of the following are true:
                // the proxy accepts deposits (isDepositable), msg.data.length == 0, and msg.value > 0
                if and(and(sload(isDepositablePosition), iszero(calldatasize)), gt(callvalue, 0)) {
                    // Equivalent Solidity code for emitting the event:
                    // emit ProxyDeposit(msg.sender, msg.value);

                    let logData := mload(0x40) // free memory pointer
                    mstore(logData, caller) // add 'msg.sender' to the log data (first event param)
                    mstore(add(logData, 0x20), callvalue) // add 'msg.value' to the log data (second event param)

                    // Emit an event with one topic to identify the event: keccak256('ProxyDeposit(address,uint256)') = 0x15ee...dee1
                    log1(logData, 0x40, 0x15eeaa57c7bd188c1388020bcadc2c436ec60d647d36ef5b9eb3c742217ddee1)

                    stop() // Stop. Exits execution context
                }

                // If any of above checks failed, revert the execution (if ETH was sent, it is returned to the sender)
                revert(0, 0)
            }
        }

        address target = implementation();
        delegatedFwd(target, msg.data);
    }
}

// File: contracts/kernel/KernelProxy.sol

pragma solidity 0.4.24;







contract KernelProxy is IKernelEvents, KernelStorage, KernelAppIds, KernelNamespaceConstants, IsContract, DepositableDelegateProxy {
    /**
    * @dev KernelProxy is a proxy contract to a kernel implementation. The implementation
    *      can update the reference, which effectively upgrades the contract
    * @param _kernelImpl Address of the contract used as implementation for kernel
    */
    constructor(IKernel _kernelImpl) public {
        require(isContract(address(_kernelImpl)));
        apps[KERNEL_CORE_NAMESPACE][KERNEL_CORE_APP_ID] = _kernelImpl;

        // Note that emitting this event is important for verifying that a KernelProxy instance
        // was never upgraded to a malicious Kernel logic contract over its lifespan.
        // This starts the "chain of trust", that can be followed through later SetApp() events
        // emitted during kernel upgrades.
        emit SetApp(KERNEL_CORE_NAMESPACE, KERNEL_CORE_APP_ID, _kernelImpl);
    }

    /**
     * @dev ERC897, whether it is a forwarding (1) or an upgradeable (2) proxy
     */
    function proxyType() public pure returns (uint256 proxyTypeId) {
        return UPGRADEABLE;
    }

    /**
    * @dev ERC897, the address the proxy would delegate calls to
    */
    function implementation() public view returns (address) {
        return apps[KERNEL_CORE_NAMESPACE][KERNEL_CORE_APP_ID];
    }
}

// File: contracts/acl/IACL.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


interface IACL {
    function initialize(address permissionsCreator) external;

    // TODO: this should be external
    // See https://github.com/ethereum/solidity/issues/4832
    function hasPermission(address who, address where, bytes32 what, bytes how) public view returns (bool);
}

// File: contracts/common/IVaultRecoverable.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


interface IVaultRecoverable {
    event RecoverToVault(address indexed vault, address indexed token, uint256 amount);

    function transferToVault(address token) external;

    function allowRecoverability(address token) external view returns (bool);
    function getRecoveryVault() external view returns (address);
}

// File: contracts/kernel/IKernel.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;




interface IKernelEvents {
    event SetApp(bytes32 indexed namespace, bytes32 indexed appId, address app);
}


// This should be an interface, but interfaces can't inherit yet :(
contract IKernel is IKernelEvents, IVaultRecoverable {
    function acl() public view returns (IACL);
    function hasPermission(address who, address where, bytes32 what, bytes how) public view returns (bool);

    function setApp(bytes32 namespace, bytes32 appId, address app) public;
    function getApp(bytes32 namespace, bytes32 appId) public view returns (address);
}

// File: contracts/kernel/KernelConstants.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


contract KernelAppIds {
    /* Hardcoded constants to save gas
    bytes32 internal constant KERNEL_CORE_APP_ID = apmNamehash("kernel");
    bytes32 internal constant KERNEL_DEFAULT_ACL_APP_ID = apmNamehash("acl");
    bytes32 internal constant KERNEL_DEFAULT_VAULT_APP_ID = apmNamehash("vault");
    */
    bytes32 internal constant KERNEL_CORE_APP_ID = 0x3b4bf6bf3ad5000ecf0f989d5befde585c6860fea3e574a4fab4c49d1c177d9c;
    bytes32 internal constant KERNEL_DEFAULT_ACL_APP_ID = 0xe3262375f45a6e2026b7e7b18c2b807434f2508fe1a2a3dfb493c7df8f4aad6a;
    bytes32 internal constant KERNEL_DEFAULT_VAULT_APP_ID = 0x7e852e0fcfce6551c13800f1e7476f982525c2b5277ba14b24339c68416336d1;
}


contract KernelNamespaceConstants {
    /* Hardcoded constants to save gas
    bytes32 internal constant KERNEL_CORE_NAMESPACE = keccak256("core");
    bytes32 internal constant KERNEL_APP_BASES_NAMESPACE = keccak256("base");
    bytes32 internal constant KERNEL_APP_ADDR_NAMESPACE = keccak256("app");
    */
    bytes32 internal constant KERNEL_CORE_NAMESPACE = 0xc681a85306374a5ab27f0bbc385296a54bcd314a1948b6cf61c4ea1bc44bb9f8;
    bytes32 internal constant KERNEL_APP_BASES_NAMESPACE = 0xf1f3eb40f5bc1ad1344716ced8b8a0431d840b5783aea1fd01786bc26f35ac0f;
    bytes32 internal constant KERNEL_APP_ADDR_NAMESPACE = 0xd6f028ca0e8edb4a8c9757ca4fdccab25fa1e0317da1188108f7d2dee14902fb;
}

// File: contracts/kernel/KernelStorage.sol

pragma solidity 0.4.24;


contract KernelStorage {
    // namespace => app id => address
    mapping (bytes32 => mapping (bytes32 => address)) public apps;
    bytes32 public recoveryVaultAppId;
}

// File: contracts/acl/ACLSyntaxSugar.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


contract ACLSyntaxSugar {
    function arr() internal pure returns (uint256[]) {
        return new uint256[](0);
    }

    function arr(bytes32 _a) internal pure returns (uint256[] r) {
        return arr(uint256(_a));
    }

    function arr(bytes32 _a, bytes32 _b) internal pure returns (uint256[] r) {
        return arr(uint256(_a), uint256(_b));
    }

    function arr(address _a) internal pure returns (uint256[] r) {
        return arr(uint256(_a));
    }

    function arr(address _a, address _b) internal pure returns (uint256[] r) {
        return arr(uint256(_a), uint256(_b));
    }

    function arr(address _a, uint256 _b, uint256 _c) internal pure returns (uint256[] r) {
        return arr(uint256(_a), _b, _c);
    }

    function arr(address _a, uint256 _b, uint256 _c, uint256 _d) internal pure returns (uint256[] r) {
        return arr(uint256(_a), _b, _c, _d);
    }

    function arr(address _a, uint256 _b) internal pure returns (uint256[] r) {
        return arr(uint256(_a), uint256(_b));
    }

    function arr(address _a, address _b, uint256 _c, uint256 _d, uint256 _e) internal pure returns (uint256[] r) {
        return arr(uint256(_a), uint256(_b), _c, _d, _e);
    }

    function arr(address _a, address _b, address _c) internal pure returns (uint256[] r) {
        return arr(uint256(_a), uint256(_b), uint256(_c));
    }

    function arr(address _a, address _b, uint256 _c) internal pure returns (uint256[] r) {
        return arr(uint256(_a), uint256(_b), uint256(_c));
    }

    function arr(uint256 _a) internal pure returns (uint256[] r) {
        r = new uint256[](1);
        r[0] = _a;
    }

    function arr(uint256 _a, uint256 _b) internal pure returns (uint256[] r) {
        r = new uint256[](2);
        r[0] = _a;
        r[1] = _b;
    }

    function arr(uint256 _a, uint256 _b, uint256 _c) internal pure returns (uint256[] r) {
        r = new uint256[](3);
        r[0] = _a;
        r[1] = _b;
        r[2] = _c;
    }

    function arr(uint256 _a, uint256 _b, uint256 _c, uint256 _d) internal pure returns (uint256[] r) {
        r = new uint256[](4);
        r[0] = _a;
        r[1] = _b;
        r[2] = _c;
        r[3] = _d;
    }

    function arr(uint256 _a, uint256 _b, uint256 _c, uint256 _d, uint256 _e) internal pure returns (uint256[] r) {
        r = new uint256[](5);
        r[0] = _a;
        r[1] = _b;
        r[2] = _c;
        r[3] = _d;
        r[4] = _e;
    }
}


contract ACLHelpers {
    function decodeParamOp(uint256 _x) internal pure returns (uint8 b) {
        return uint8(_x >> (8 * 30));
    }

    function decodeParamId(uint256 _x) internal pure returns (uint8 b) {
        return uint8(_x >> (8 * 31));
    }

    function decodeParamsList(uint256 _x) internal pure returns (uint32 a, uint32 b, uint32 c) {
        a = uint32(_x);
        b = uint32(_x >> (8 * 4));
        c = uint32(_x >> (8 * 8));
    }
}

// File: contracts/common/ConversionHelpers.sol

pragma solidity ^0.4.24;


library ConversionHelpers {
    string private constant ERROR_IMPROPER_LENGTH = "CONVERSION_IMPROPER_LENGTH";

    function dangerouslyCastUintArrayToBytes(uint256[] memory _input) internal pure returns (bytes memory output) {
        // Force cast the uint256[] into a bytes array, by overwriting its length
        // Note that the bytes array doesn't need to be initialized as we immediately overwrite it
        // with the input and a new length. The input becomes invalid from this point forward.
        uint256 byteLength = _input.length * 32;
        assembly {
            output := _input
            mstore(output, byteLength)
        }
    }

    function dangerouslyCastBytesToUintArray(bytes memory _input) internal pure returns (uint256[] memory output) {
        // Force cast the bytes array into a uint256[], by overwriting its length
        // Note that the uint256[] doesn't need to be initialized as we immediately overwrite it
        // with the input and a new length. The input becomes invalid from this point forward.
        uint256 intsLength = _input.length / 32;
        require(_input.length == intsLength * 32, ERROR_IMPROPER_LENGTH);

        assembly {
            output := _input
            mstore(output, intsLength)
        }
    }
}

// File: contracts/common/IsContract.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


contract IsContract {
    /*
    * NOTE: this should NEVER be used for authentication
    * (see pitfalls: https://github.com/fergarrui/ethereum-security/tree/master/contracts/extcodesize).
    *
    * This is only intended to be used as a sanity check that an address is actually a contract,
    * RATHER THAN an address not being a contract.
    */
    function isContract(address _target) internal view returns (bool) {
        if (_target == address(0)) {
            return false;
        }

        uint256 size;
        assembly { size := extcodesize(_target) }
        return size > 0;
    }
}

// File: contracts/common/Uint256Helpers.sol

pragma solidity ^0.4.24;


library Uint256Helpers {
    uint256 private constant MAX_UINT64 = uint64(-1);

    string private constant ERROR_NUMBER_TOO_BIG = "UINT64_NUMBER_TOO_BIG";

    function toUint64(uint256 a) internal pure returns (uint64) {
        require(a <= MAX_UINT64, ERROR_NUMBER_TOO_BIG);
        return uint64(a);
    }
}

// File: contracts/common/TimeHelpers.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;



contract TimeHelpers {
    using Uint256Helpers for uint256;

    /**
    * @dev Returns the current block number.
    *      Using a function rather than `block.number` allows us to easily mock the block number in
    *      tests.
    */
    function getBlockNumber() internal view returns (uint256) {
        return block.number;
    }

    /**
    * @dev Returns the current block number, converted to uint64.
    *      Using a function rather than `block.number` allows us to easily mock the block number in
    *      tests.
    */
    function getBlockNumber64() internal view returns (uint64) {
        return getBlockNumber().toUint64();
    }

    /**
    * @dev Returns the current timestamp.
    *      Using a function rather than `block.timestamp` allows us to easily mock it in
    *      tests.
    */
    function getTimestamp() internal view returns (uint256) {
        return block.timestamp; // solium-disable-line security/no-block-members
    }

    /**
    * @dev Returns the current timestamp, converted to uint64.
    *      Using a function rather than `block.timestamp` allows us to easily mock it in
    *      tests.
    */
    function getTimestamp64() internal view returns (uint64) {
        return getTimestamp().toUint64();
    }
}

// File: contracts/common/UnstructuredStorage.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


library UnstructuredStorage {
    function getStorageBool(bytes32 position) internal view returns (bool data) {
        assembly { data := sload(position) }
    }

    function getStorageAddress(bytes32 position) internal view returns (address data) {
        assembly { data := sload(position) }
    }

    function getStorageBytes32(bytes32 position) internal view returns (bytes32 data) {
        assembly { data := sload(position) }
    }

    function getStorageUint256(bytes32 position) internal view returns (uint256 data) {
        assembly { data := sload(position) }
    }

    function setStorageBool(bytes32 position, bool data) internal {
        assembly { sstore(position, data) }
    }

    function setStorageAddress(bytes32 position, address data) internal {
        assembly { sstore(position, data) }
    }

    function setStorageBytes32(bytes32 position, bytes32 data) internal {
        assembly { sstore(position, data) }
    }

    function setStorageUint256(bytes32 position, uint256 data) internal {
        assembly { sstore(position, data) }
    }
}

// File: contracts/common/Initializable.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;




contract Initializable is TimeHelpers {
    using UnstructuredStorage for bytes32;

    // keccak256("aragonOS.initializable.initializationBlock")
    bytes32 internal constant INITIALIZATION_BLOCK_POSITION = 0xebb05b386a8d34882b8711d156f463690983dc47815980fb82aeeff1aa43579e;

    string private constant ERROR_ALREADY_INITIALIZED = "INIT_ALREADY_INITIALIZED";
    string private constant ERROR_NOT_INITIALIZED = "INIT_NOT_INITIALIZED";

    modifier onlyInit {
        require(getInitializationBlock() == 0, ERROR_ALREADY_INITIALIZED);
        _;
    }

    modifier isInitialized {
        require(hasInitialized(), ERROR_NOT_INITIALIZED);
        _;
    }

    /**
    * @return Block number in which the contract was initialized
    */
    function getInitializationBlock() public view returns (uint256) {
        return INITIALIZATION_BLOCK_POSITION.getStorageUint256();
    }

    /**
    * @return Whether the contract has been initialized by the time of the current block
    */
    function hasInitialized() public view returns (bool) {
        uint256 initializationBlock = getInitializationBlock();
        return initializationBlock != 0 && getBlockNumber() >= initializationBlock;
    }

    /**
    * @dev Function to be called by top level contract after initialization has finished.
    */
    function initialized() internal onlyInit {
        INITIALIZATION_BLOCK_POSITION.setStorageUint256(getBlockNumber());
    }

    /**
    * @dev Function to be called by top level contract after initialization to enable the contract
    *      at a future block number rather than immediately.
    */
    function initializedAt(uint256 _blockNumber) internal onlyInit {
        INITIALIZATION_BLOCK_POSITION.setStorageUint256(_blockNumber);
    }
}

// File: contracts/common/Petrifiable.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;



contract Petrifiable is Initializable {
    // Use block UINT256_MAX (which should be never) as the initializable date
    uint256 internal constant PETRIFIED_BLOCK = uint256(-1);

    function isPetrified() public view returns (bool) {
        return getInitializationBlock() == PETRIFIED_BLOCK;
    }

    /**
    * @dev Function to be called by top level contract to prevent being initialized.
    *      Useful for freezing base contracts when they're used behind proxies.
    */
    function petrify() internal onlyInit {
        initializedAt(PETRIFIED_BLOCK);
    }
}

// File: contracts/lib/token/ERC20.sol

// See https://github.com/OpenZeppelin/openzeppelin-solidity/blob/a9f910d34f0ab33a1ae5e714f69f9596a02b4d91/contracts/token/ERC20/ERC20.sol

pragma solidity ^0.4.24;


/**
 * @title ERC20 interface
 * @dev see https://github.com/ethereum/EIPs/issues/20
 */
contract ERC20 {
    function totalSupply() public view returns (uint256);

    function balanceOf(address _who) public view returns (uint256);

    function allowance(address _owner, address _spender)
        public view returns (uint256);

    function transfer(address _to, uint256 _value) public returns (bool);

    function approve(address _spender, uint256 _value)
        public returns (bool);

    function transferFrom(address _from, address _to, uint256 _value)
        public returns (bool);

    event Transfer(
        address indexed from,
        address indexed to,
        uint256 value
    );

    event Approval(
        address indexed owner,
        address indexed spender,
        uint256 value
    );
}

// File: contracts/common/EtherTokenConstant.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


// aragonOS and aragon-apps rely on address(0) to denote native ETH, in
// contracts where both tokens and ETH are accepted
contract EtherTokenConstant {
    address internal constant ETH = address(0);
}

// File: contracts/common/SafeERC20.sol

// Inspired by AdEx (https://github.com/AdExNetwork/adex-protocol-eth/blob/b9df617829661a7518ee10f4cb6c4108659dd6d5/contracts/libs/SafeERC20.sol)
// and 0x (https://github.com/0xProject/0x-monorepo/blob/737d1dc54d72872e24abce5a1dbe1b66d35fa21a/contracts/protocol/contracts/protocol/AssetProxy/ERC20Proxy.sol#L143)

pragma solidity ^0.4.24;



library SafeERC20 {
    // Before 0.5, solidity has a mismatch between `address.transfer()` and `token.transfer()`:
    // https://github.com/ethereum/solidity/issues/3544
    bytes4 private constant TRANSFER_SELECTOR = 0xa9059cbb;

    string private constant ERROR_TOKEN_BALANCE_REVERTED = "SAFE_ERC_20_BALANCE_REVERTED";
    string private constant ERROR_TOKEN_ALLOWANCE_REVERTED = "SAFE_ERC_20_ALLOWANCE_REVERTED";

    function invokeAndCheckSuccess(address _addr, bytes memory _calldata)
        private
        returns (bool)
    {
        bool ret;
        assembly {
            let ptr := mload(0x40)    // free memory pointer

            let success := call(
                gas,                  // forward all gas
                _addr,                // address
                0,                    // no value
                add(_calldata, 0x20), // calldata start
                mload(_calldata),     // calldata length
                ptr,                  // write output over free memory
                0x20                  // uint256 return
            )

            if gt(success, 0) {
                // Check number of bytes returned from last function call
                switch returndatasize

                // No bytes returned: assume success
                case 0 {
                    ret := 1
                }

                // 32 bytes returned: check if non-zero
                case 0x20 {
                    // Only return success if returned data was true
                    // Already have output in ptr
                    ret := eq(mload(ptr), 1)
                }

                // Not sure what was returned: don't mark as success
                default { }
            }
        }
        return ret;
    }

    function staticInvoke(address _addr, bytes memory _calldata)
        private
        view
        returns (bool, uint256)
    {
        bool success;
        uint256 ret;
        assembly {
            let ptr := mload(0x40)    // free memory pointer

            success := staticcall(
                gas,                  // forward all gas
                _addr,                // address
                add(_calldata, 0x20), // calldata start
                mload(_calldata),     // calldata length
                ptr,                  // write output over free memory
                0x20                  // uint256 return
            )

            if gt(success, 0) {
                ret := mload(ptr)
            }
        }
        return (success, ret);
    }

    /**
    * @dev Same as a standards-compliant ERC20.transfer() that never reverts (returns false).
    *      Note that this makes an external call to the token.
    */
    function safeTransfer(ERC20 _token, address _to, uint256 _amount) internal returns (bool) {
        bytes memory transferCallData = abi.encodeWithSelector(
            TRANSFER_SELECTOR,
            _to,
            _amount
        );
        return invokeAndCheckSuccess(_token, transferCallData);
    }

    /**
    * @dev Same as a standards-compliant ERC20.transferFrom() that never reverts (returns false).
    *      Note that this makes an external call to the token.
    */
    function safeTransferFrom(ERC20 _token, address _from, address _to, uint256 _amount) internal returns (bool) {
        bytes memory transferFromCallData = abi.encodeWithSelector(
            _token.transferFrom.selector,
            _from,
            _to,
            _amount
        );
        return invokeAndCheckSuccess(_token, transferFromCallData);
    }

    /**
    * @dev Same as a standards-compliant ERC20.approve() that never reverts (returns false).
    *      Note that this makes an external call to the token.
    */
    function safeApprove(ERC20 _token, address _spender, uint256 _amount) internal returns (bool) {
        bytes memory approveCallData = abi.encodeWithSelector(
            _token.approve.selector,
            _spender,
            _amount
        );
        return invokeAndCheckSuccess(_token, approveCallData);
    }

    /**
    * @dev Static call into ERC20.balanceOf().
    * Reverts if the call fails for some reason (should never fail).
    */
    function staticBalanceOf(ERC20 _token, address _owner) internal view returns (uint256) {
        bytes memory balanceOfCallData = abi.encodeWithSelector(
            _token.balanceOf.selector,
            _owner
        );

        (bool success, uint256 tokenBalance) = staticInvoke(_token, balanceOfCallData);
        require(success, ERROR_TOKEN_BALANCE_REVERTED);

        return tokenBalance;
    }

    /**
    * @dev Static call into ERC20.allowance().
    * Reverts if the call fails for some reason (should never fail).
    */
    function staticAllowance(ERC20 _token, address _owner, address _spender) internal view returns (uint256) {
        bytes memory allowanceCallData = abi.encodeWithSelector(
            _token.allowance.selector,
            _owner,
            _spender
        );

        (bool success, uint256 allowance) = staticInvoke(_token, allowanceCallData);
        require(success, ERROR_TOKEN_ALLOWANCE_REVERTED);

        return allowance;
    }

    /**
    * @dev Static call into ERC20.totalSupply().
    * Reverts if the call fails for some reason (should never fail).
    */
    function staticTotalSupply(ERC20 _token) internal view returns (uint256) {
        bytes memory totalSupplyCallData = abi.encodeWithSelector(_token.totalSupply.selector);

        (bool success, uint256 totalSupply) = staticInvoke(_token, totalSupplyCallData);
        require(success, ERROR_TOKEN_ALLOWANCE_REVERTED);

        return totalSupply;
    }
}

// File: contracts/common/VaultRecoverable.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;







contract VaultRecoverable is IVaultRecoverable, EtherTokenConstant, IsContract {
    using SafeERC20 for ERC20;

    string private constant ERROR_DISALLOWED = "RECOVER_DISALLOWED";
    string private constant ERROR_VAULT_NOT_CONTRACT = "RECOVER_VAULT_NOT_CONTRACT";
    string private constant ERROR_TOKEN_TRANSFER_FAILED = "RECOVER_TOKEN_TRANSFER_FAILED";

    /**
     * @notice Send funds to recovery Vault. This contract should never receive funds,
     *         but in case it does, this function allows one to recover them.
     * @param _token Token balance to be sent to recovery vault.
     */
    function transferToVault(address _token) external {
        require(allowRecoverability(_token), ERROR_DISALLOWED);
        address vault = getRecoveryVault();
        require(isContract(vault), ERROR_VAULT_NOT_CONTRACT);

        uint256 balance;
        if (_token == ETH) {
            balance = address(this).balance;
            vault.transfer(balance);
        } else {
            ERC20 token = ERC20(_token);
            balance = token.staticBalanceOf(this);
            require(token.safeTransfer(vault, balance), ERROR_TOKEN_TRANSFER_FAILED);
        }

        emit RecoverToVault(vault, _token, balance);
    }

    /**
    * @dev By default deriving from AragonApp makes it recoverable
    * @param token Token address that would be recovered
    * @return bool whether the app allows the recovery
    */
    function allowRecoverability(address token) public view returns (bool) {
        return true;
    }

    // Cast non-implemented interface to be public so we can use it internally
    function getRecoveryVault() public view returns (address);
}

// File: contracts/apps/AppStorage.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;




contract AppStorage {
    using UnstructuredStorage for bytes32;

    /* Hardcoded constants to save gas
    bytes32 internal constant KERNEL_POSITION = keccak256("aragonOS.appStorage.kernel");
    bytes32 internal constant APP_ID_POSITION = keccak256("aragonOS.appStorage.appId");
    */
    bytes32 internal constant KERNEL_POSITION = 0x4172f0f7d2289153072b0a6ca36959e0cbe2efc3afe50fc81636caa96338137b;
    bytes32 internal constant APP_ID_POSITION = 0xd625496217aa6a3453eecb9c3489dc5a53e6c67b444329ea2b2cbc9ff547639b;

    function kernel() public view returns (IKernel) {
        return IKernel(KERNEL_POSITION.getStorageAddress());
    }

    function appId() public view returns (bytes32) {
        return APP_ID_POSITION.getStorageBytes32();
    }

    function setKernel(IKernel _kernel) internal {
        KERNEL_POSITION.setStorageAddress(address(_kernel));
    }

    function setAppId(bytes32 _appId) internal {
        APP_ID_POSITION.setStorageBytes32(_appId);
    }
}

// File: contracts/lib/misc/ERCProxy.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


contract ERCProxy {
    uint256 internal constant FORWARDING = 1;
    uint256 internal constant UPGRADEABLE = 2;

    function proxyType() public pure returns (uint256 proxyTypeId);
    function implementation() public view returns (address codeAddr);
}

// File: contracts/common/DelegateProxy.sol

pragma solidity 0.4.24;




contract DelegateProxy is ERCProxy, IsContract {
    uint256 internal constant FWD_GAS_LIMIT = 10000;

    /**
    * @dev Performs a delegatecall and returns whatever the delegatecall returned (entire context execution will return!)
    * @param _dst Destination address to perform the delegatecall
    * @param _calldata Calldata for the delegatecall
    */
    function delegatedFwd(address _dst, bytes _calldata) internal {
        require(isContract(_dst));
        uint256 fwdGasLimit = FWD_GAS_LIMIT;

        assembly {
            let result := delegatecall(sub(gas, fwdGasLimit), _dst, add(_calldata, 0x20), mload(_calldata), 0, 0)
            let size := returndatasize
            let ptr := mload(0x40)
            returndatacopy(ptr, 0, size)

            // revert instead of invalid() bc if the underlying call failed with invalid() it already wasted gas.
            // if the call returned error data, forward it
            switch result case 0 { revert(ptr, size) }
            default { return(ptr, size) }
        }
    }
}

// File: contracts/common/DepositableStorage.sol

pragma solidity 0.4.24;



contract DepositableStorage {
    using UnstructuredStorage for bytes32;

    // keccak256("aragonOS.depositableStorage.depositable")
    bytes32 internal constant DEPOSITABLE_POSITION = 0x665fd576fbbe6f247aff98f5c94a561e3f71ec2d3c988d56f12d342396c50cea;

    function isDepositable() public view returns (bool) {
        return DEPOSITABLE_POSITION.getStorageBool();
    }

    function setDepositable(bool _depositable) internal {
        DEPOSITABLE_POSITION.setStorageBool(_depositable);
    }
}

// File: contracts/common/DepositableDelegateProxy.sol

pragma solidity 0.4.24;




contract DepositableDelegateProxy is DepositableStorage, DelegateProxy {
    event ProxyDeposit(address sender, uint256 value);

    function () external payable {
        uint256 forwardGasThreshold = FWD_GAS_LIMIT;
        bytes32 isDepositablePosition = DEPOSITABLE_POSITION;

        // Optimized assembly implementation to prevent EIP-1884 from breaking deposits, reference code in Solidity:
        // https://github.com/aragon/aragonOS/blob/v4.2.1/contracts/common/DepositableDelegateProxy.sol#L10-L20
        assembly {
            // Continue only if the gas left is lower than the threshold for forwarding to the implementation code,
            // otherwise continue outside of the assembly block.
            if lt(gas, forwardGasThreshold) {
                // Only accept the deposit and emit an event if all of the following are true:
                // the proxy accepts deposits (isDepositable), msg.data.length == 0, and msg.value > 0
                if and(and(sload(isDepositablePosition), iszero(calldatasize)), gt(callvalue, 0)) {
                    // Equivalent Solidity code for emitting the event:
                    // emit ProxyDeposit(msg.sender, msg.value);

                    let logData := mload(0x40) // free memory pointer
                    mstore(logData, caller) // add 'msg.sender' to the log data (first event param)
                    mstore(add(logData, 0x20), callvalue) // add 'msg.value' to the log data (second event param)

                    // Emit an event with one topic to identify the event: keccak256('ProxyDeposit(address,uint256)') = 0x15ee...dee1
                    log1(logData, 0x40, 0x15eeaa57c7bd188c1388020bcadc2c436ec60d647d36ef5b9eb3c742217ddee1)

                    stop() // Stop. Exits execution context
                }

                // If any of above checks failed, revert the execution (if ETH was sent, it is returned to the sender)
                revert(0, 0)
            }
        }

        address target = implementation();
        delegatedFwd(target, msg.data);
    }
}

// File: contracts/apps/AppProxyBase.sol

pragma solidity 0.4.24;






contract AppProxyBase is AppStorage, DepositableDelegateProxy, KernelNamespaceConstants {
    /**
    * @dev Initialize AppProxy
    * @param _kernel Reference to organization kernel for the app
    * @param _appId Identifier for app
    * @param _initializePayload Payload for call to be made after setup to initialize
    */
    constructor(IKernel _kernel, bytes32 _appId, bytes _initializePayload) public {
        setKernel(_kernel);
        setAppId(_appId);

        // Implicit check that kernel is actually a Kernel
        // The EVM doesn't actually provide a way for us to make sure, but we can force a revert to
        // occur if the kernel is set to 0x0 or a non-code address when we try to call a method on
        // it.
        address appCode = getAppBase(_appId);

        // If initialize payload is provided, it will be executed
        if (_initializePayload.length > 0) {
            require(isContract(appCode));
            // Cannot make delegatecall as a delegateproxy.delegatedFwd as it
            // returns ending execution context and halts contract deployment
            require(appCode.delegatecall(_initializePayload));
        }
    }

    function getAppBase(bytes32 _appId) internal view returns (address) {
        return kernel().getApp(KERNEL_APP_BASES_NAMESPACE, _appId);
    }
}

// File: contracts/apps/AppProxyUpgradeable.sol

pragma solidity 0.4.24;



contract AppProxyUpgradeable is AppProxyBase {
    /**
    * @dev Initialize AppProxyUpgradeable (makes it an upgradeable Aragon app)
    * @param _kernel Reference to organization kernel for the app
    * @param _appId Identifier for app
    * @param _initializePayload Payload for call to be made after setup to initialize
    */
    constructor(IKernel _kernel, bytes32 _appId, bytes _initializePayload)
        AppProxyBase(_kernel, _appId, _initializePayload)
        public // solium-disable-line visibility-first
    {
        // solium-disable-previous-line no-empty-blocks
    }

    /**
     * @dev ERC897, the address the proxy would delegate calls to
     */
    function implementation() public view returns (address) {
        return getAppBase(appId());
    }

    /**
     * @dev ERC897, whether it is a forwarding (1) or an upgradeable (2) proxy
     */
    function proxyType() public pure returns (uint256 proxyTypeId) {
        return UPGRADEABLE;
    }
}

// File: contracts/apps/AppProxyPinned.sol

pragma solidity 0.4.24;





contract AppProxyPinned is IsContract, AppProxyBase {
    using UnstructuredStorage for bytes32;

    // keccak256("aragonOS.appStorage.pinnedCode")
    bytes32 internal constant PINNED_CODE_POSITION = 0xdee64df20d65e53d7f51cb6ab6d921a0a6a638a91e942e1d8d02df28e31c038e;

    /**
    * @dev Initialize AppProxyPinned (makes it an un-upgradeable Aragon app)
    * @param _kernel Reference to organization kernel for the app
    * @param _appId Identifier for app
    * @param _initializePayload Payload for call to be made after setup to initialize
    */
    constructor(IKernel _kernel, bytes32 _appId, bytes _initializePayload)
        AppProxyBase(_kernel, _appId, _initializePayload)
        public // solium-disable-line visibility-first
    {
        setPinnedCode(getAppBase(_appId));
        require(isContract(pinnedCode()));
    }

    /**
     * @dev ERC897, the address the proxy would delegate calls to
     */
    function implementation() public view returns (address) {
        return pinnedCode();
    }

    /**
     * @dev ERC897, whether it is a forwarding (1) or an upgradeable (2) proxy
     */
    function proxyType() public pure returns (uint256 proxyTypeId) {
        return FORWARDING;
    }

    function setPinnedCode(address _pinnedCode) internal {
        PINNED_CODE_POSITION.setStorageAddress(_pinnedCode);
    }

    function pinnedCode() internal view returns (address) {
        return PINNED_CODE_POSITION.getStorageAddress();
    }
}

// File: contracts/factory/AppProxyFactory.sol

pragma solidity 0.4.24;




contract AppProxyFactory {
    event NewAppProxy(address proxy, bool isUpgradeable, bytes32 appId);

    /**
    * @notice Create a new upgradeable app instance on `_kernel` with identifier `_appId`
    * @param _kernel App's Kernel reference
    * @param _appId Identifier for app
    * @return AppProxyUpgradeable
    */
    function newAppProxy(IKernel _kernel, bytes32 _appId) public returns (AppProxyUpgradeable) {
        return newAppProxy(_kernel, _appId, new bytes(0));
    }

    /**
    * @notice Create a new upgradeable app instance on `_kernel` with identifier `_appId` and initialization payload `_initializePayload`
    * @param _kernel App's Kernel reference
    * @param _appId Identifier for app
    * @return AppProxyUpgradeable
    */
    function newAppProxy(IKernel _kernel, bytes32 _appId, bytes _initializePayload) public returns (AppProxyUpgradeable) {
        AppProxyUpgradeable proxy = new AppProxyUpgradeable(_kernel, _appId, _initializePayload);
        emit NewAppProxy(address(proxy), true, _appId);
        return proxy;
    }

    /**
    * @notice Create a new pinned app instance on `_kernel` with identifier `_appId`
    * @param _kernel App's Kernel reference
    * @param _appId Identifier for app
    * @return AppProxyPinned
    */
    function newAppProxyPinned(IKernel _kernel, bytes32 _appId) public returns (AppProxyPinned) {
        return newAppProxyPinned(_kernel, _appId, new bytes(0));
    }

    /**
    * @notice Create a new pinned app instance on `_kernel` with identifier `_appId` and initialization payload `_initializePayload`
    * @param _kernel App's Kernel reference
    * @param _appId Identifier for app
    * @param _initializePayload Proxy initialization payload
    * @return AppProxyPinned
    */
    function newAppProxyPinned(IKernel _kernel, bytes32 _appId, bytes _initializePayload) public returns (AppProxyPinned) {
        AppProxyPinned proxy = new AppProxyPinned(_kernel, _appId, _initializePayload);
        emit NewAppProxy(address(proxy), false, _appId);
        return proxy;
    }
}

// File: contracts/kernel/Kernel.sol

pragma solidity 0.4.24;













// solium-disable-next-line max-len
contract Kernel is IKernel, KernelStorage, KernelAppIds, KernelNamespaceConstants, Petrifiable, IsContract, VaultRecoverable, AppProxyFactory, ACLSyntaxSugar {
    /* Hardcoded constants to save gas
    bytes32 public constant APP_MANAGER_ROLE = keccak256("APP_MANAGER_ROLE");
    */
    bytes32 public constant APP_MANAGER_ROLE = 0xb6d92708f3d4817afc106147d969e229ced5c46e65e0a5002a0d391287762bd0;

    string private constant ERROR_APP_NOT_CONTRACT = "KERNEL_APP_NOT_CONTRACT";
    string private constant ERROR_INVALID_APP_CHANGE = "KERNEL_INVALID_APP_CHANGE";
    string private constant ERROR_AUTH_FAILED = "KERNEL_AUTH_FAILED";

    /**
    * @dev Constructor that allows the deployer to choose if the base instance should be petrified immediately.
    * @param _shouldPetrify Immediately petrify this instance so that it can never be initialized
    */
    constructor(bool _shouldPetrify) public {
        if (_shouldPetrify) {
            petrify();
        }
    }

    /**
    * @dev Initialize can only be called once. It saves the block number in which it was initialized.
    * @notice Initialize this kernel instance along with its ACL and set `_permissionsCreator` as the entity that can create other permissions
    * @param _baseAcl Address of base ACL app
    * @param _permissionsCreator Entity that will be given permission over createPermission
    */
    function initialize(IACL _baseAcl, address _permissionsCreator) public onlyInit {
        initialized();

        // Set ACL base
        _setApp(KERNEL_APP_BASES_NAMESPACE, KERNEL_DEFAULT_ACL_APP_ID, _baseAcl);

        // Create ACL instance and attach it as the default ACL app
        IACL acl = IACL(newAppProxy(this, KERNEL_DEFAULT_ACL_APP_ID));
        acl.initialize(_permissionsCreator);
        _setApp(KERNEL_APP_ADDR_NAMESPACE, KERNEL_DEFAULT_ACL_APP_ID, acl);

        recoveryVaultAppId = KERNEL_DEFAULT_VAULT_APP_ID;
    }

    /**
    * @dev Create a new instance of an app linked to this kernel
    * @notice Create a new upgradeable instance of `_appId` app linked to the Kernel, setting its code to `_appBase`
    * @param _appId Identifier for app
    * @param _appBase Address of the app's base implementation
    * @return AppProxy instance
    */
    function newAppInstance(bytes32 _appId, address _appBase)
        public
        auth(APP_MANAGER_ROLE, arr(KERNEL_APP_BASES_NAMESPACE, _appId))
        returns (ERCProxy appProxy)
    {
        return newAppInstance(_appId, _appBase, new bytes(0), false);
    }

    /**
    * @dev Create a new instance of an app linked to this kernel and set its base
    *      implementation if it was not already set
    * @notice Create a new upgradeable instance of `_appId` app linked to the Kernel, setting its code to `_appBase`. `_setDefault ? 'Also sets it as the default app instance.':''`
    * @param _appId Identifier for app
    * @param _appBase Address of the app's base implementation
    * @param _initializePayload Payload for call made by the proxy during its construction to initialize
    * @param _setDefault Whether the app proxy app is the default one.
    *        Useful when the Kernel needs to know of an instance of a particular app,
    *        like Vault for escape hatch mechanism.
    * @return AppProxy instance
    */
    function newAppInstance(bytes32 _appId, address _appBase, bytes _initializePayload, bool _setDefault)
        public
        auth(APP_MANAGER_ROLE, arr(KERNEL_APP_BASES_NAMESPACE, _appId))
        returns (ERCProxy appProxy)
    {
        _setAppIfNew(KERNEL_APP_BASES_NAMESPACE, _appId, _appBase);
        appProxy = newAppProxy(this, _appId, _initializePayload);
        // By calling setApp directly and not the internal functions, we make sure the params are checked
        // and it will only succeed if sender has permissions to set something to the namespace.
        if (_setDefault) {
            setApp(KERNEL_APP_ADDR_NAMESPACE, _appId, appProxy);
        }
    }

    /**
    * @dev Create a new pinned instance of an app linked to this kernel
    * @notice Create a new non-upgradeable instance of `_appId` app linked to the Kernel, setting its code to `_appBase`.
    * @param _appId Identifier for app
    * @param _appBase Address of the app's base implementation
    * @return AppProxy instance
    */
    function newPinnedAppInstance(bytes32 _appId, address _appBase)
        public
        auth(APP_MANAGER_ROLE, arr(KERNEL_APP_BASES_NAMESPACE, _appId))
        returns (ERCProxy appProxy)
    {
        return newPinnedAppInstance(_appId, _appBase, new bytes(0), false);
    }

    /**
    * @dev Create a new pinned instance of an app linked to this kernel and set
    *      its base implementation if it was not already set
    * @notice Create a new non-upgradeable instance of `_appId` app linked to the Kernel, setting its code to `_appBase`. `_setDefault ? 'Also sets it as the default app instance.':''`
    * @param _appId Identifier for app
    * @param _appBase Address of the app's base implementation
    * @param _initializePayload Payload for call made by the proxy during its construction to initialize
    * @param _setDefault Whether the app proxy app is the default one.
    *        Useful when the Kernel needs to know of an instance of a particular app,
    *        like Vault for escape hatch mechanism.
    * @return AppProxy instance
    */
    function newPinnedAppInstance(bytes32 _appId, address _appBase, bytes _initializePayload, bool _setDefault)
        public
        auth(APP_MANAGER_ROLE, arr(KERNEL_APP_BASES_NAMESPACE, _appId))
        returns (ERCProxy appProxy)
    {
        _setAppIfNew(KERNEL_APP_BASES_NAMESPACE, _appId, _appBase);
        appProxy = newAppProxyPinned(this, _appId, _initializePayload);
        // By calling setApp directly and not the internal functions, we make sure the params are checked
        // and it will only succeed if sender has permissions to set something to the namespace.
        if (_setDefault) {
            setApp(KERNEL_APP_ADDR_NAMESPACE, _appId, appProxy);
        }
    }

    /**
    * @dev Set the resolving address of an app instance or base implementation
    * @notice Set the resolving address of `_appId` in namespace `_namespace` to `_app`
    * @param _namespace App namespace to use
    * @param _appId Identifier for app
    * @param _app Address of the app instance or base implementation
    * @return ID of app
    */
    function setApp(bytes32 _namespace, bytes32 _appId, address _app)
        public
        auth(APP_MANAGER_ROLE, arr(_namespace, _appId))
    {
        _setApp(_namespace, _appId, _app);
    }

    /**
    * @dev Set the default vault id for the escape hatch mechanism
    * @param _recoveryVaultAppId Identifier of the recovery vault app
    */
    function setRecoveryVaultAppId(bytes32 _recoveryVaultAppId)
        public
        auth(APP_MANAGER_ROLE, arr(KERNEL_APP_ADDR_NAMESPACE, _recoveryVaultAppId))
    {
        recoveryVaultAppId = _recoveryVaultAppId;
    }

    // External access to default app id and namespace constants to mimic default getters for constants
    /* solium-disable function-order, mixedcase */
    function CORE_NAMESPACE() external pure returns (bytes32) { return KERNEL_CORE_NAMESPACE; }
    function APP_BASES_NAMESPACE() external pure returns (bytes32) { return KERNEL_APP_BASES_NAMESPACE; }
    function APP_ADDR_NAMESPACE() external pure returns (bytes32) { return KERNEL_APP_ADDR_NAMESPACE; }
    function KERNEL_APP_ID() external pure returns (bytes32) { return KERNEL_CORE_APP_ID; }
    function DEFAULT_ACL_APP_ID() external pure returns (bytes32) { return KERNEL_DEFAULT_ACL_APP_ID; }
    /* solium-enable function-order, mixedcase */

    /**
    * @dev Get the address of an app instance or base implementation
    * @param _namespace App namespace to use
    * @param _appId Identifier for app
    * @return Address of the app
    */
    function getApp(bytes32 _namespace, bytes32 _appId) public view returns (address) {
        return apps[_namespace][_appId];
    }

    /**
    * @dev Get the address of the recovery Vault instance (to recover funds)
    * @return Address of the Vault
    */
    function getRecoveryVault() public view returns (address) {
        return apps[KERNEL_APP_ADDR_NAMESPACE][recoveryVaultAppId];
    }

    /**
    * @dev Get the installed ACL app
    * @return ACL app
    */
    function acl() public view returns (IACL) {
        return IACL(getApp(KERNEL_APP_ADDR_NAMESPACE, KERNEL_DEFAULT_ACL_APP_ID));
    }

    /**
    * @dev Function called by apps to check ACL on kernel or to check permission status
    * @param _who Sender of the original call
    * @param _where Address of the app
    * @param _what Identifier for a group of actions in app
    * @param _how Extra data for ACL auth
    * @return Boolean indicating whether the ACL allows the role or not.
    *         Always returns false if the kernel hasn't been initialized yet.
    */
    function hasPermission(address _who, address _where, bytes32 _what, bytes _how) public view returns (bool) {
        IACL defaultAcl = acl();
        return address(defaultAcl) != address(0) && // Poor man's initialization check (saves gas)
            defaultAcl.hasPermission(_who, _where, _what, _how);
    }

    function _setApp(bytes32 _namespace, bytes32 _appId, address _app) internal {
        require(isContract(_app), ERROR_APP_NOT_CONTRACT);
        apps[_namespace][_appId] = _app;
        emit SetApp(_namespace, _appId, _app);
    }

    function _setAppIfNew(bytes32 _namespace, bytes32 _appId, address _app) internal {
        address app = getApp(_namespace, _appId);
        if (app != address(0)) {
            // The only way to set an app is if it passes the isContract check, so no need to check it again
            require(app == _app, ERROR_INVALID_APP_CHANGE);
        } else {
            _setApp(_namespace, _appId, _app);
        }
    }

    modifier auth(bytes32 _role, uint256[] memory _params) {
        require(
            hasPermission(msg.sender, address(this), _role, ConversionHelpers.dangerouslyCastUintArrayToBytes(_params)),
            ERROR_AUTH_FAILED
        );
        _;
    }
}

// File: @aragon/os/contracts/common/UnstructuredStorage.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


library UnstructuredStorage {
    function getStorageBool(bytes32 position) internal view returns (bool data) {
        assembly { data := sload(position) }
    }

    function getStorageAddress(bytes32 position) internal view returns (address data) {
        assembly { data := sload(position) }
    }

    function getStorageBytes32(bytes32 position) internal view returns (bytes32 data) {
        assembly { data := sload(position) }
    }

    function getStorageUint256(bytes32 position) internal view returns (uint256 data) {
        assembly { data := sload(position) }
    }

    function setStorageBool(bytes32 position, bool data) internal {
        assembly { sstore(position, data) }
    }

    function setStorageAddress(bytes32 position, address data) internal {
        assembly { sstore(position, data) }
    }

    function setStorageBytes32(bytes32 position, bytes32 data) internal {
        assembly { sstore(position, data) }
    }

    function setStorageUint256(bytes32 position, uint256 data) internal {
        assembly { sstore(position, data) }
    }
}

// File: @aragon/os/contracts/acl/IACL.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


interface IACL {
    function initialize(address permissionsCreator) external;

    // TODO: this should be external
    // See https://github.com/ethereum/solidity/issues/4832
    function hasPermission(address who, address where, bytes32 what, bytes how) public view returns (bool);
}

// File: @aragon/os/contracts/common/IVaultRecoverable.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


interface IVaultRecoverable {
    event RecoverToVault(address indexed vault, address indexed token, uint256 amount);

    function transferToVault(address token) external;

    function allowRecoverability(address token) external view returns (bool);
    function getRecoveryVault() external view returns (address);
}

// File: @aragon/os/contracts/kernel/IKernel.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;




interface IKernelEvents {
    event SetApp(bytes32 indexed namespace, bytes32 indexed appId, address app);
}


// This should be an interface, but interfaces can't inherit yet :(
contract IKernel is IKernelEvents, IVaultRecoverable {
    function acl() public view returns (IACL);
    function hasPermission(address who, address where, bytes32 what, bytes how) public view returns (bool);

    function setApp(bytes32 namespace, bytes32 appId, address app) public;
    function getApp(bytes32 namespace, bytes32 appId) public view returns (address);
}

// File: @aragon/os/contracts/apps/AppStorage.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;




contract AppStorage {
    using UnstructuredStorage for bytes32;

    /* Hardcoded constants to save gas
    bytes32 internal constant KERNEL_POSITION = keccak256("aragonOS.appStorage.kernel");
    bytes32 internal constant APP_ID_POSITION = keccak256("aragonOS.appStorage.appId");
    */
    bytes32 internal constant KERNEL_POSITION = 0x4172f0f7d2289153072b0a6ca36959e0cbe2efc3afe50fc81636caa96338137b;
    bytes32 internal constant APP_ID_POSITION = 0xd625496217aa6a3453eecb9c3489dc5a53e6c67b444329ea2b2cbc9ff547639b;

    function kernel() public view returns (IKernel) {
        return IKernel(KERNEL_POSITION.getStorageAddress());
    }

    function appId() public view returns (bytes32) {
        return APP_ID_POSITION.getStorageBytes32();
    }

    function setKernel(IKernel _kernel) internal {
        KERNEL_POSITION.setStorageAddress(address(_kernel));
    }

    function setAppId(bytes32 _appId) internal {
        APP_ID_POSITION.setStorageBytes32(_appId);
    }
}

// File: @aragon/os/contracts/acl/ACLSyntaxSugar.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


contract ACLSyntaxSugar {
    function arr() internal pure returns (uint256[]) {
        return new uint256[](0);
    }

    function arr(bytes32 _a) internal pure returns (uint256[] r) {
        return arr(uint256(_a));
    }

    function arr(bytes32 _a, bytes32 _b) internal pure returns (uint256[] r) {
        return arr(uint256(_a), uint256(_b));
    }

    function arr(address _a) internal pure returns (uint256[] r) {
        return arr(uint256(_a));
    }

    function arr(address _a, address _b) internal pure returns (uint256[] r) {
        return arr(uint256(_a), uint256(_b));
    }

    function arr(address _a, uint256 _b, uint256 _c) internal pure returns (uint256[] r) {
        return arr(uint256(_a), _b, _c);
    }

    function arr(address _a, uint256 _b, uint256 _c, uint256 _d) internal pure returns (uint256[] r) {
        return arr(uint256(_a), _b, _c, _d);
    }

    function arr(address _a, uint256 _b) internal pure returns (uint256[] r) {
        return arr(uint256(_a), uint256(_b));
    }

    function arr(address _a, address _b, uint256 _c, uint256 _d, uint256 _e) internal pure returns (uint256[] r) {
        return arr(uint256(_a), uint256(_b), _c, _d, _e);
    }

    function arr(address _a, address _b, address _c) internal pure returns (uint256[] r) {
        return arr(uint256(_a), uint256(_b), uint256(_c));
    }

    function arr(address _a, address _b, uint256 _c) internal pure returns (uint256[] r) {
        return arr(uint256(_a), uint256(_b), uint256(_c));
    }

    function arr(uint256 _a) internal pure returns (uint256[] r) {
        r = new uint256[](1);
        r[0] = _a;
    }

    function arr(uint256 _a, uint256 _b) internal pure returns (uint256[] r) {
        r = new uint256[](2);
        r[0] = _a;
        r[1] = _b;
    }

    function arr(uint256 _a, uint256 _b, uint256 _c) internal pure returns (uint256[] r) {
        r = new uint256[](3);
        r[0] = _a;
        r[1] = _b;
        r[2] = _c;
    }

    function arr(uint256 _a, uint256 _b, uint256 _c, uint256 _d) internal pure returns (uint256[] r) {
        r = new uint256[](4);
        r[0] = _a;
        r[1] = _b;
        r[2] = _c;
        r[3] = _d;
    }

    function arr(uint256 _a, uint256 _b, uint256 _c, uint256 _d, uint256 _e) internal pure returns (uint256[] r) {
        r = new uint256[](5);
        r[0] = _a;
        r[1] = _b;
        r[2] = _c;
        r[3] = _d;
        r[4] = _e;
    }
}


contract ACLHelpers {
    function decodeParamOp(uint256 _x) internal pure returns (uint8 b) {
        return uint8(_x >> (8 * 30));
    }

    function decodeParamId(uint256 _x) internal pure returns (uint8 b) {
        return uint8(_x >> (8 * 31));
    }

    function decodeParamsList(uint256 _x) internal pure returns (uint32 a, uint32 b, uint32 c) {
        a = uint32(_x);
        b = uint32(_x >> (8 * 4));
        c = uint32(_x >> (8 * 8));
    }
}

// File: @aragon/os/contracts/common/Uint256Helpers.sol

pragma solidity ^0.4.24;


library Uint256Helpers {
    uint256 private constant MAX_UINT64 = uint64(-1);

    string private constant ERROR_NUMBER_TOO_BIG = "UINT64_NUMBER_TOO_BIG";

    function toUint64(uint256 a) internal pure returns (uint64) {
        require(a <= MAX_UINT64, ERROR_NUMBER_TOO_BIG);
        return uint64(a);
    }
}

// File: @aragon/os/contracts/common/TimeHelpers.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;



contract TimeHelpers {
    using Uint256Helpers for uint256;

    /**
    * @dev Returns the current block number.
    *      Using a function rather than `block.number` allows us to easily mock the block number in
    *      tests.
    */
    function getBlockNumber() internal view returns (uint256) {
        return block.number;
    }

    /**
    * @dev Returns the current block number, converted to uint64.
    *      Using a function rather than `block.number` allows us to easily mock the block number in
    *      tests.
    */
    function getBlockNumber64() internal view returns (uint64) {
        return getBlockNumber().toUint64();
    }

    /**
    * @dev Returns the current timestamp.
    *      Using a function rather than `block.timestamp` allows us to easily mock it in
    *      tests.
    */
    function getTimestamp() internal view returns (uint256) {
        return block.timestamp; // solium-disable-line security/no-block-members
    }

    /**
    * @dev Returns the current timestamp, converted to uint64.
    *      Using a function rather than `block.timestamp` allows us to easily mock it in
    *      tests.
    */
    function getTimestamp64() internal view returns (uint64) {
        return getTimestamp().toUint64();
    }
}

// File: @aragon/os/contracts/common/Initializable.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;




contract Initializable is TimeHelpers {
    using UnstructuredStorage for bytes32;

    // keccak256("aragonOS.initializable.initializationBlock")
    bytes32 internal constant INITIALIZATION_BLOCK_POSITION = 0xebb05b386a8d34882b8711d156f463690983dc47815980fb82aeeff1aa43579e;

    string private constant ERROR_ALREADY_INITIALIZED = "INIT_ALREADY_INITIALIZED";
    string private constant ERROR_NOT_INITIALIZED = "INIT_NOT_INITIALIZED";

    modifier onlyInit {
        require(getInitializationBlock() == 0, ERROR_ALREADY_INITIALIZED);
        _;
    }

    modifier isInitialized {
        require(hasInitialized(), ERROR_NOT_INITIALIZED);
        _;
    }

    /**
    * @return Block number in which the contract was initialized
    */
    function getInitializationBlock() public view returns (uint256) {
        return INITIALIZATION_BLOCK_POSITION.getStorageUint256();
    }

    /**
    * @return Whether the contract has been initialized by the time of the current block
    */
    function hasInitialized() public view returns (bool) {
        uint256 initializationBlock = getInitializationBlock();
        return initializationBlock != 0 && getBlockNumber() >= initializationBlock;
    }

    /**
    * @dev Function to be called by top level contract after initialization has finished.
    */
    function initialized() internal onlyInit {
        INITIALIZATION_BLOCK_POSITION.setStorageUint256(getBlockNumber());
    }

    /**
    * @dev Function to be called by top level contract after initialization to enable the contract
    *      at a future block number rather than immediately.
    */
    function initializedAt(uint256 _blockNumber) internal onlyInit {
        INITIALIZATION_BLOCK_POSITION.setStorageUint256(_blockNumber);
    }
}

// File: @aragon/os/contracts/common/Petrifiable.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;



contract Petrifiable is Initializable {
    // Use block UINT256_MAX (which should be never) as the initializable date
    uint256 internal constant PETRIFIED_BLOCK = uint256(-1);

    function isPetrified() public view returns (bool) {
        return getInitializationBlock() == PETRIFIED_BLOCK;
    }

    /**
    * @dev Function to be called by top level contract to prevent being initialized.
    *      Useful for freezing base contracts when they're used behind proxies.
    */
    function petrify() internal onlyInit {
        initializedAt(PETRIFIED_BLOCK);
    }
}

// File: @aragon/os/contracts/common/Autopetrified.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;



contract Autopetrified is Petrifiable {
    constructor() public {
        // Immediately petrify base (non-proxy) instances of inherited contracts on deploy.
        // This renders them uninitializable (and unusable without a proxy).
        petrify();
    }
}

// File: @aragon/os/contracts/common/ConversionHelpers.sol

pragma solidity ^0.4.24;


library ConversionHelpers {
    string private constant ERROR_IMPROPER_LENGTH = "CONVERSION_IMPROPER_LENGTH";

    function dangerouslyCastUintArrayToBytes(uint256[] memory _input) internal pure returns (bytes memory output) {
        // Force cast the uint256[] into a bytes array, by overwriting its length
        // Note that the bytes array doesn't need to be initialized as we immediately overwrite it
        // with the input and a new length. The input becomes invalid from this point forward.
        uint256 byteLength = _input.length * 32;
        assembly {
            output := _input
            mstore(output, byteLength)
        }
    }

    function dangerouslyCastBytesToUintArray(bytes memory _input) internal pure returns (uint256[] memory output) {
        // Force cast the bytes array into a uint256[], by overwriting its length
        // Note that the uint256[] doesn't need to be initialized as we immediately overwrite it
        // with the input and a new length. The input becomes invalid from this point forward.
        uint256 intsLength = _input.length / 32;
        require(_input.length == intsLength * 32, ERROR_IMPROPER_LENGTH);

        assembly {
            output := _input
            mstore(output, intsLength)
        }
    }
}

// File: @aragon/os/contracts/common/ReentrancyGuard.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;



contract ReentrancyGuard {
    using UnstructuredStorage for bytes32;

    /* Hardcoded constants to save gas
    bytes32 internal constant REENTRANCY_MUTEX_POSITION = keccak256("aragonOS.reentrancyGuard.mutex");
    */
    bytes32 private constant REENTRANCY_MUTEX_POSITION = 0xe855346402235fdd185c890e68d2c4ecad599b88587635ee285bce2fda58dacb;

    string private constant ERROR_REENTRANT = "REENTRANCY_REENTRANT_CALL";

    modifier nonReentrant() {
        // Ensure mutex is unlocked
        require(!REENTRANCY_MUTEX_POSITION.getStorageBool(), ERROR_REENTRANT);

        // Lock mutex before function call
        REENTRANCY_MUTEX_POSITION.setStorageBool(true);

        // Perform function call
        _;

        // Unlock mutex after function call
        REENTRANCY_MUTEX_POSITION.setStorageBool(false);
    }
}

// File: @aragon/os/contracts/lib/token/ERC20.sol

// See https://github.com/OpenZeppelin/openzeppelin-solidity/blob/a9f910d34f0ab33a1ae5e714f69f9596a02b4d91/contracts/token/ERC20/ERC20.sol

pragma solidity ^0.4.24;


/**
 * @title ERC20 interface
 * @dev see https://github.com/ethereum/EIPs/issues/20
 */
contract ERC20 {
    function totalSupply() public view returns (uint256);

    function balanceOf(address _who) public view returns (uint256);

    function allowance(address _owner, address _spender)
        public view returns (uint256);

    function transfer(address _to, uint256 _value) public returns (bool);

    function approve(address _spender, uint256 _value)
        public returns (bool);

    function transferFrom(address _from, address _to, uint256 _value)
        public returns (bool);

    event Transfer(
        address indexed from,
        address indexed to,
        uint256 value
    );

    event Approval(
        address indexed owner,
        address indexed spender,
        uint256 value
    );
}

// File: @aragon/os/contracts/common/EtherTokenConstant.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


// aragonOS and aragon-apps rely on address(0) to denote native ETH, in
// contracts where both tokens and ETH are accepted
contract EtherTokenConstant {
    address internal constant ETH = address(0);
}

// File: @aragon/os/contracts/common/IsContract.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


contract IsContract {
    /*
    * NOTE: this should NEVER be used for authentication
    * (see pitfalls: https://github.com/fergarrui/ethereum-security/tree/master/contracts/extcodesize).
    *
    * This is only intended to be used as a sanity check that an address is actually a contract,
    * RATHER THAN an address not being a contract.
    */
    function isContract(address _target) internal view returns (bool) {
        if (_target == address(0)) {
            return false;
        }

        uint256 size;
        assembly { size := extcodesize(_target) }
        return size > 0;
    }
}

// File: @aragon/os/contracts/common/SafeERC20.sol

// Inspired by AdEx (https://github.com/AdExNetwork/adex-protocol-eth/blob/b9df617829661a7518ee10f4cb6c4108659dd6d5/contracts/libs/SafeERC20.sol)
// and 0x (https://github.com/0xProject/0x-monorepo/blob/737d1dc54d72872e24abce5a1dbe1b66d35fa21a/contracts/protocol/contracts/protocol/AssetProxy/ERC20Proxy.sol#L143)

pragma solidity ^0.4.24;



library SafeERC20 {
    // Before 0.5, solidity has a mismatch between `address.transfer()` and `token.transfer()`:
    // https://github.com/ethereum/solidity/issues/3544
    bytes4 private constant TRANSFER_SELECTOR = 0xa9059cbb;

    string private constant ERROR_TOKEN_BALANCE_REVERTED = "SAFE_ERC_20_BALANCE_REVERTED";
    string private constant ERROR_TOKEN_ALLOWANCE_REVERTED = "SAFE_ERC_20_ALLOWANCE_REVERTED";

    function invokeAndCheckSuccess(address _addr, bytes memory _calldata)
        private
        returns (bool)
    {
        bool ret;
        assembly {
            let ptr := mload(0x40)    // free memory pointer

            let success := call(
                gas,                  // forward all gas
                _addr,                // address
                0,                    // no value
                add(_calldata, 0x20), // calldata start
                mload(_calldata),     // calldata length
                ptr,                  // write output over free memory
                0x20                  // uint256 return
            )

            if gt(success, 0) {
                // Check number of bytes returned from last function call
                switch returndatasize

                // No bytes returned: assume success
                case 0 {
                    ret := 1
                }

                // 32 bytes returned: check if non-zero
                case 0x20 {
                    // Only return success if returned data was true
                    // Already have output in ptr
                    ret := eq(mload(ptr), 1)
                }

                // Not sure what was returned: don't mark as success
                default { }
            }
        }
        return ret;
    }

    function staticInvoke(address _addr, bytes memory _calldata)
        private
        view
        returns (bool, uint256)
    {
        bool success;
        uint256 ret;
        assembly {
            let ptr := mload(0x40)    // free memory pointer

            success := staticcall(
                gas,                  // forward all gas
                _addr,                // address
                add(_calldata, 0x20), // calldata start
                mload(_calldata),     // calldata length
                ptr,                  // write output over free memory
                0x20                  // uint256 return
            )

            if gt(success, 0) {
                ret := mload(ptr)
            }
        }
        return (success, ret);
    }

    /**
    * @dev Same as a standards-compliant ERC20.transfer() that never reverts (returns false).
    *      Note that this makes an external call to the token.
    */
    function safeTransfer(ERC20 _token, address _to, uint256 _amount) internal returns (bool) {
        bytes memory transferCallData = abi.encodeWithSelector(
            TRANSFER_SELECTOR,
            _to,
            _amount
        );
        return invokeAndCheckSuccess(_token, transferCallData);
    }

    /**
    * @dev Same as a standards-compliant ERC20.transferFrom() that never reverts (returns false).
    *      Note that this makes an external call to the token.
    */
    function safeTransferFrom(ERC20 _token, address _from, address _to, uint256 _amount) internal returns (bool) {
        bytes memory transferFromCallData = abi.encodeWithSelector(
            _token.transferFrom.selector,
            _from,
            _to,
            _amount
        );
        return invokeAndCheckSuccess(_token, transferFromCallData);
    }

    /**
    * @dev Same as a standards-compliant ERC20.approve() that never reverts (returns false).
    *      Note that this makes an external call to the token.
    */
    function safeApprove(ERC20 _token, address _spender, uint256 _amount) internal returns (bool) {
        bytes memory approveCallData = abi.encodeWithSelector(
            _token.approve.selector,
            _spender,
            _amount
        );
        return invokeAndCheckSuccess(_token, approveCallData);
    }

    /**
    * @dev Static call into ERC20.balanceOf().
    * Reverts if the call fails for some reason (should never fail).
    */
    function staticBalanceOf(ERC20 _token, address _owner) internal view returns (uint256) {
        bytes memory balanceOfCallData = abi.encodeWithSelector(
            _token.balanceOf.selector,
            _owner
        );

        (bool success, uint256 tokenBalance) = staticInvoke(_token, balanceOfCallData);
        require(success, ERROR_TOKEN_BALANCE_REVERTED);

        return tokenBalance;
    }

    /**
    * @dev Static call into ERC20.allowance().
    * Reverts if the call fails for some reason (should never fail).
    */
    function staticAllowance(ERC20 _token, address _owner, address _spender) internal view returns (uint256) {
        bytes memory allowanceCallData = abi.encodeWithSelector(
            _token.allowance.selector,
            _owner,
            _spender
        );

        (bool success, uint256 allowance) = staticInvoke(_token, allowanceCallData);
        require(success, ERROR_TOKEN_ALLOWANCE_REVERTED);

        return allowance;
    }
}

// File: @aragon/os/contracts/common/VaultRecoverable.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;







contract VaultRecoverable is IVaultRecoverable, EtherTokenConstant, IsContract {
    using SafeERC20 for ERC20;

    string private constant ERROR_DISALLOWED = "RECOVER_DISALLOWED";
    string private constant ERROR_VAULT_NOT_CONTRACT = "RECOVER_VAULT_NOT_CONTRACT";
    string private constant ERROR_TOKEN_TRANSFER_FAILED = "RECOVER_TOKEN_TRANSFER_FAILED";

    /**
     * @notice Send funds to recovery Vault. This contract should never receive funds,
     *         but in case it does, this function allows one to recover them.
     * @param _token Token balance to be sent to recovery vault.
     */
    function transferToVault(address _token) external {
        require(allowRecoverability(_token), ERROR_DISALLOWED);
        address vault = getRecoveryVault();
        require(isContract(vault), ERROR_VAULT_NOT_CONTRACT);

        uint256 balance;
        if (_token == ETH) {
            balance = address(this).balance;
            vault.transfer(balance);
        } else {
            ERC20 token = ERC20(_token);
            balance = token.staticBalanceOf(this);
            require(token.safeTransfer(vault, balance), ERROR_TOKEN_TRANSFER_FAILED);
        }

        emit RecoverToVault(vault, _token, balance);
    }

    /**
    * @dev By default deriving from AragonApp makes it recoverable
    * @param token Token address that would be recovered
    * @return bool whether the app allows the recovery
    */
    function allowRecoverability(address token) public view returns (bool) {
        return true;
    }

    // Cast non-implemented interface to be public so we can use it internally
    function getRecoveryVault() public view returns (address);
}

// File: @aragon/os/contracts/evmscript/IEVMScriptExecutor.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


interface IEVMScriptExecutor {
    function execScript(bytes script, bytes input, address[] blacklist) external returns (bytes);
    function executorType() external pure returns (bytes32);
}

// File: @aragon/os/contracts/evmscript/IEVMScriptRegistry.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;



contract EVMScriptRegistryConstants {
    /* Hardcoded constants to save gas
    bytes32 internal constant EVMSCRIPT_REGISTRY_APP_ID = apmNamehash("evmreg");
    */
    bytes32 internal constant EVMSCRIPT_REGISTRY_APP_ID = 0xddbcfd564f642ab5627cf68b9b7d374fb4f8a36e941a75d89c87998cef03bd61;
}


interface IEVMScriptRegistry {
    function addScriptExecutor(IEVMScriptExecutor executor) external returns (uint id);
    function disableScriptExecutor(uint256 executorId) external;

    // TODO: this should be external
    // See https://github.com/ethereum/solidity/issues/4832
    function getScriptExecutor(bytes script) public view returns (IEVMScriptExecutor);
}

// File: @aragon/os/contracts/kernel/KernelConstants.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


contract KernelAppIds {
    /* Hardcoded constants to save gas
    bytes32 internal constant KERNEL_CORE_APP_ID = apmNamehash("kernel");
    bytes32 internal constant KERNEL_DEFAULT_ACL_APP_ID = apmNamehash("acl");
    bytes32 internal constant KERNEL_DEFAULT_VAULT_APP_ID = apmNamehash("vault");
    */
    bytes32 internal constant KERNEL_CORE_APP_ID = 0x3b4bf6bf3ad5000ecf0f989d5befde585c6860fea3e574a4fab4c49d1c177d9c;
    bytes32 internal constant KERNEL_DEFAULT_ACL_APP_ID = 0xe3262375f45a6e2026b7e7b18c2b807434f2508fe1a2a3dfb493c7df8f4aad6a;
    bytes32 internal constant KERNEL_DEFAULT_VAULT_APP_ID = 0x7e852e0fcfce6551c13800f1e7476f982525c2b5277ba14b24339c68416336d1;
}


contract KernelNamespaceConstants {
    /* Hardcoded constants to save gas
    bytes32 internal constant KERNEL_CORE_NAMESPACE = keccak256("core");
    bytes32 internal constant KERNEL_APP_BASES_NAMESPACE = keccak256("base");
    bytes32 internal constant KERNEL_APP_ADDR_NAMESPACE = keccak256("app");
    */
    bytes32 internal constant KERNEL_CORE_NAMESPACE = 0xc681a85306374a5ab27f0bbc385296a54bcd314a1948b6cf61c4ea1bc44bb9f8;
    bytes32 internal constant KERNEL_APP_BASES_NAMESPACE = 0xf1f3eb40f5bc1ad1344716ced8b8a0431d840b5783aea1fd01786bc26f35ac0f;
    bytes32 internal constant KERNEL_APP_ADDR_NAMESPACE = 0xd6f028ca0e8edb4a8c9757ca4fdccab25fa1e0317da1188108f7d2dee14902fb;
}

// File: @aragon/os/contracts/evmscript/EVMScriptRunner.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;







contract EVMScriptRunner is AppStorage, Initializable, EVMScriptRegistryConstants, KernelNamespaceConstants {
    string private constant ERROR_EXECUTOR_UNAVAILABLE = "EVMRUN_EXECUTOR_UNAVAILABLE";
    string private constant ERROR_PROTECTED_STATE_MODIFIED = "EVMRUN_PROTECTED_STATE_MODIFIED";

    /* This is manually crafted in assembly
    string private constant ERROR_EXECUTOR_INVALID_RETURN = "EVMRUN_EXECUTOR_INVALID_RETURN";
    */

    event ScriptResult(address indexed executor, bytes script, bytes input, bytes returnData);

    function getEVMScriptExecutor(bytes _script) public view returns (IEVMScriptExecutor) {
        return IEVMScriptExecutor(getEVMScriptRegistry().getScriptExecutor(_script));
    }

    function getEVMScriptRegistry() public view returns (IEVMScriptRegistry) {
        address registryAddr = kernel().getApp(KERNEL_APP_ADDR_NAMESPACE, EVMSCRIPT_REGISTRY_APP_ID);
        return IEVMScriptRegistry(registryAddr);
    }

    function runScript(bytes _script, bytes _input, address[] _blacklist)
        internal
        isInitialized
        protectState
        returns (bytes)
    {
        IEVMScriptExecutor executor = getEVMScriptExecutor(_script);
        require(address(executor) != address(0), ERROR_EXECUTOR_UNAVAILABLE);

        bytes4 sig = executor.execScript.selector;
        bytes memory data = abi.encodeWithSelector(sig, _script, _input, _blacklist);

        bytes memory output;
        assembly {
            let success := delegatecall(
                gas,                // forward all gas
                executor,           // address
                add(data, 0x20),    // calldata start
                mload(data),        // calldata length
                0,                  // don't write output (we'll handle this ourselves)
                0                   // don't write output
            )

            output := mload(0x40) // free mem ptr get

            switch success
            case 0 {
                // If the call errored, forward its full error data
                returndatacopy(output, 0, returndatasize)
                revert(output, returndatasize)
            }
            default {
                switch gt(returndatasize, 0x3f)
                case 0 {
                    // Need at least 0x40 bytes returned for properly ABI-encoded bytes values,
                    // revert with "EVMRUN_EXECUTOR_INVALID_RETURN"
                    // See remix: doing a `revert("EVMRUN_EXECUTOR_INVALID_RETURN")` always results in
                    // this memory layout
                    mstore(output, 0x08c379a000000000000000000000000000000000000000000000000000000000)         // error identifier
                    mstore(add(output, 0x04), 0x0000000000000000000000000000000000000000000000000000000000000020) // starting offset
                    mstore(add(output, 0x24), 0x000000000000000000000000000000000000000000000000000000000000001e) // reason length
                    mstore(add(output, 0x44), 0x45564d52554e5f4558454355544f525f494e56414c49445f52455455524e0000) // reason

                    revert(output, 100) // 100 = 4 + 3 * 32 (error identifier + 3 words for the ABI encoded error)
                }
                default {
                    // Copy result
                    //
                    // Needs to perform an ABI decode for the expected `bytes` return type of
                    // `executor.execScript()` as solidity will automatically ABI encode the returned bytes as:
                    //    [ position of the first dynamic length return value = 0x20 (32 bytes) ]
                    //    [ output length (32 bytes) ]
                    //    [ output content (N bytes) ]
                    //
                    // Perform the ABI decode by ignoring the first 32 bytes of the return data
                    let copysize := sub(returndatasize, 0x20)
                    returndatacopy(output, 0x20, copysize)

                    mstore(0x40, add(output, copysize)) // free mem ptr set
                }
            }
        }

        emit ScriptResult(address(executor), _script, _input, output);

        return output;
    }

    modifier protectState {
        address preKernel = address(kernel());
        bytes32 preAppId = appId();
        _; // exec
        require(address(kernel()) == preKernel, ERROR_PROTECTED_STATE_MODIFIED);
        require(appId() == preAppId, ERROR_PROTECTED_STATE_MODIFIED);
    }
}

// File: @aragon/os/contracts/apps/AragonApp.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;









// Contracts inheriting from AragonApp are, by default, immediately petrified upon deployment so
// that they can never be initialized.
// Unless overriden, this behaviour enforces those contracts to be usable only behind an AppProxy.
// ReentrancyGuard, EVMScriptRunner, and ACLSyntaxSugar are not directly used by this contract, but
// are included so that they are automatically usable by subclassing contracts
contract AragonApp is AppStorage, Autopetrified, VaultRecoverable, ReentrancyGuard, EVMScriptRunner, ACLSyntaxSugar {
    string private constant ERROR_AUTH_FAILED = "APP_AUTH_FAILED";

    modifier auth(bytes32 _role) {
        require(canPerform(msg.sender, _role, new uint256[](0)), ERROR_AUTH_FAILED);
        _;
    }

    modifier authP(bytes32 _role, uint256[] _params) {
        require(canPerform(msg.sender, _role, _params), ERROR_AUTH_FAILED);
        _;
    }

    /**
    * @dev Check whether an action can be performed by a sender for a particular role on this app
    * @param _sender Sender of the call
    * @param _role Role on this app
    * @param _params Permission params for the role
    * @return Boolean indicating whether the sender has the permissions to perform the action.
    *         Always returns false if the app hasn't been initialized yet.
    */
    function canPerform(address _sender, bytes32 _role, uint256[] _params) public view returns (bool) {
        if (!hasInitialized()) {
            return false;
        }

        IKernel linkedKernel = kernel();
        if (address(linkedKernel) == address(0)) {
            return false;
        }

        return linkedKernel.hasPermission(
            _sender,
            address(this),
            _role,
            ConversionHelpers.dangerouslyCastUintArrayToBytes(_params)
        );
    }

    /**
    * @dev Get the recovery vault for the app
    * @return Recovery vault address for the app
    */
    function getRecoveryVault() public view returns (address) {
        // Funds recovery via a vault is only available when used with a kernel
        return kernel().getRecoveryVault(); // if kernel is not set, it will revert
    }
}

// File: @aragon/os/contracts/common/IForwarder.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


interface IForwarder {
    function isForwarder() external pure returns (bool);

    // TODO: this should be external
    // See https://github.com/ethereum/solidity/issues/4832
    function canForward(address sender, bytes evmCallScript) public view returns (bool);

    // TODO: this should be external
    // See https://github.com/ethereum/solidity/issues/4832
    function forward(bytes evmCallScript) public;
}

// File: @aragon/os/contracts/lib/math/SafeMath.sol

// See https://github.com/OpenZeppelin/openzeppelin-solidity/blob/d51e38758e1d985661534534d5c61e27bece5042/contracts/math/SafeMath.sol
// Adapted to use pragma ^0.4.24 and satisfy our linter rules

pragma solidity ^0.4.24;


/**
 * @title SafeMath
 * @dev Math operations with safety checks that revert on error
 */
library SafeMath {
    string private constant ERROR_ADD_OVERFLOW = "MATH_ADD_OVERFLOW";
    string private constant ERROR_SUB_UNDERFLOW = "MATH_SUB_UNDERFLOW";
    string private constant ERROR_MUL_OVERFLOW = "MATH_MUL_OVERFLOW";
    string private constant ERROR_DIV_ZERO = "MATH_DIV_ZERO";

    /**
    * @dev Multiplies two numbers, reverts on overflow.
    */
    function mul(uint256 _a, uint256 _b) internal pure returns (uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
        if (_a == 0) {
            return 0;
        }

        uint256 c = _a * _b;
        require(c / _a == _b, ERROR_MUL_OVERFLOW);

        return c;
    }

    /**
    * @dev Integer division of two numbers truncating the quotient, reverts on division by zero.
    */
    function div(uint256 _a, uint256 _b) internal pure returns (uint256) {
        require(_b > 0, ERROR_DIV_ZERO); // Solidity only automatically asserts when dividing by 0
        uint256 c = _a / _b;
        // assert(_a == _b * c + _a % _b); // There is no case in which this doesn't hold

        return c;
    }

    /**
    * @dev Subtracts two numbers, reverts on overflow (i.e. if subtrahend is greater than minuend).
    */
    function sub(uint256 _a, uint256 _b) internal pure returns (uint256) {
        require(_b <= _a, ERROR_SUB_UNDERFLOW);
        uint256 c = _a - _b;

        return c;
    }

    /**
    * @dev Adds two numbers, reverts on overflow.
    */
    function add(uint256 _a, uint256 _b) internal pure returns (uint256) {
        uint256 c = _a + _b;
        require(c >= _a, ERROR_ADD_OVERFLOW);

        return c;
    }

    /**
    * @dev Divides two numbers and returns the remainder (unsigned integer modulo),
    * reverts when dividing by zero.
    */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b != 0, ERROR_DIV_ZERO);
        return a % b;
    }
}

// File: @aragon/apps-shared-minime/contracts/ITokenController.sol

pragma solidity ^0.4.24;

/// @dev The token controller contract must implement these functions


interface ITokenController {
    /// @notice Called when `_owner` sends ether to the MiniMe Token contract
    /// @param _owner The address that sent the ether to create tokens
    /// @return True if the ether is accepted, false if it throws
    function proxyPayment(address _owner) external payable returns(bool);

    /// @notice Notifies the controller about a token transfer allowing the
    ///  controller to react if desired
    /// @param _from The origin of the transfer
    /// @param _to The destination of the transfer
    /// @param _amount The amount of the transfer
    /// @return False if the controller does not authorize the transfer
    function onTransfer(address _from, address _to, uint _amount) external returns(bool);

    /// @notice Notifies the controller about an approval allowing the
    ///  controller to react if desired
    /// @param _owner The address that calls `approve()`
    /// @param _spender The spender in the `approve()` call
    /// @param _amount The amount in the `approve()` call
    /// @return False if the controller does not authorize the approval
    function onApprove(address _owner, address _spender, uint _amount) external returns(bool);
}

// File: @aragon/apps-shared-minime/contracts/MiniMeToken.sol

pragma solidity ^0.4.24;

/*
    Copyright 2016, Jordi Baylina
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/// @title MiniMeToken Contract
/// @author Jordi Baylina
/// @dev This token contract's goal is to make it easy for anyone to clone this
///  token using the token distribution at a given block, this will allow DAO's
///  and DApps to upgrade their features in a decentralized manner without
///  affecting the original token
/// @dev It is ERC20 compliant, but still needs to under go further testing.


contract Controlled {
    /// @notice The address of the controller is the only address that can call
    ///  a function with this modifier
    modifier onlyController {
        require(msg.sender == controller);
        _;
    }

    address public controller;

    function Controlled()  public { controller = msg.sender;}

    /// @notice Changes the controller of the contract
    /// @param _newController The new controller of the contract
    function changeController(address _newController) onlyController  public {
        controller = _newController;
    }
}

contract ApproveAndCallFallBack {
    function receiveApproval(
        address from,
        uint256 _amount,
        address _token,
        bytes _data
    ) public;
}

/// @dev The actual token contract, the default controller is the msg.sender
///  that deploys the contract, so usually this token will be deployed by a
///  token controller contract, which Giveth will call a "Campaign"
contract MiniMeToken is Controlled {

    string public name;                //The Token's name: e.g. DigixDAO Tokens
    uint8 public decimals;             //Number of decimals of the smallest unit
    string public symbol;              //An identifier: e.g. REP
    string public version = "MMT_0.1"; //An arbitrary versioning scheme


    /// @dev `Checkpoint` is the structure that attaches a block number to a
    ///  given value, the block number attached is the one that last changed the
    ///  value
    struct Checkpoint {

        // `fromBlock` is the block number that the value was generated from
        uint128 fromBlock;

        // `value` is the amount of tokens at a specific block number
        uint128 value;
    }

    // `parentToken` is the Token address that was cloned to produce this token;
    //  it will be 0x0 for a token that was not cloned
    MiniMeToken public parentToken;

    // `parentSnapShotBlock` is the block number from the Parent Token that was
    //  used to determine the initial distribution of the Clone Token
    uint public parentSnapShotBlock;

    // `creationBlock` is the block number that the Clone Token was created
    uint public creationBlock;

    // `balances` is the map that tracks the balance of each address, in this
    //  contract when the balance changes the block number that the change
    //  occurred is also included in the map
    mapping (address => Checkpoint[]) balances;

    // `allowed` tracks any extra transfer rights as in all ERC20 tokens
    mapping (address => mapping (address => uint256)) allowed;

    // Tracks the history of the `totalSupply` of the token
    Checkpoint[] totalSupplyHistory;

    // Flag that determines if the token is transferable or not.
    bool public transfersEnabled;

    // The factory used to create new clone tokens
    MiniMeTokenFactory public tokenFactory;

////////////////
// Constructor
////////////////

    /// @notice Constructor to create a MiniMeToken
    /// @param _tokenFactory The address of the MiniMeTokenFactory contract that
    ///  will create the Clone token contracts, the token factory needs to be
    ///  deployed first
    /// @param _parentToken Address of the parent token, set to 0x0 if it is a
    ///  new token
    /// @param _parentSnapShotBlock Block of the parent token that will
    ///  determine the initial distribution of the clone token, set to 0 if it
    ///  is a new token
    /// @param _tokenName Name of the new token
    /// @param _decimalUnits Number of decimals of the new token
    /// @param _tokenSymbol Token Symbol for the new token
    /// @param _transfersEnabled If true, tokens will be able to be transferred
    function MiniMeToken(
        MiniMeTokenFactory _tokenFactory,
        MiniMeToken _parentToken,
        uint _parentSnapShotBlock,
        string _tokenName,
        uint8 _decimalUnits,
        string _tokenSymbol,
        bool _transfersEnabled
    )  public
    {
        tokenFactory = _tokenFactory;
        name = _tokenName;                                 // Set the name
        decimals = _decimalUnits;                          // Set the decimals
        symbol = _tokenSymbol;                             // Set the symbol
        parentToken = _parentToken;
        parentSnapShotBlock = _parentSnapShotBlock;
        transfersEnabled = _transfersEnabled;
        creationBlock = block.number;
    }


///////////////////
// ERC20 Methods
///////////////////

    /// @notice Send `_amount` tokens to `_to` from `msg.sender`
    /// @param _to The address of the recipient
    /// @param _amount The amount of tokens to be transferred
    /// @return Whether the transfer was successful or not
    function transfer(address _to, uint256 _amount) public returns (bool success) {
        require(transfersEnabled);
        return doTransfer(msg.sender, _to, _amount);
    }

    /// @notice Send `_amount` tokens to `_to` from `_from` on the condition it
    ///  is approved by `_from`
    /// @param _from The address holding the tokens being transferred
    /// @param _to The address of the recipient
    /// @param _amount The amount of tokens to be transferred
    /// @return True if the transfer was successful
    function transferFrom(address _from, address _to, uint256 _amount) public returns (bool success) {

        // The controller of this contract can move tokens around at will,
        //  this is important to recognize! Confirm that you trust the
        //  controller of this contract, which in most situations should be
        //  another open source smart contract or 0x0
        if (msg.sender != controller) {
            require(transfersEnabled);

            // The standard ERC 20 transferFrom functionality
            if (allowed[_from][msg.sender] < _amount)
                return false;
            allowed[_from][msg.sender] -= _amount;
        }
        return doTransfer(_from, _to, _amount);
    }

    /// @dev This is the actual transfer function in the token contract, it can
    ///  only be called by other functions in this contract.
    /// @param _from The address holding the tokens being transferred
    /// @param _to The address of the recipient
    /// @param _amount The amount of tokens to be transferred
    /// @return True if the transfer was successful
    function doTransfer(address _from, address _to, uint _amount) internal returns(bool) {
        if (_amount == 0) {
            return true;
        }
        require(parentSnapShotBlock < block.number);
        // Do not allow transfer to 0x0 or the token contract itself
        require((_to != 0) && (_to != address(this)));
        // If the amount being transfered is more than the balance of the
        //  account the transfer returns false
        var previousBalanceFrom = balanceOfAt(_from, block.number);
        if (previousBalanceFrom < _amount) {
            return false;
        }
        // Alerts the token controller of the transfer
        if (isContract(controller)) {
            // Adding the ` == true` makes the linter shut up so...
            require(ITokenController(controller).onTransfer(_from, _to, _amount) == true);
        }
        // First update the balance array with the new value for the address
        //  sending the tokens
        updateValueAtNow(balances[_from], previousBalanceFrom - _amount);
        // Then update the balance array with the new value for the address
        //  receiving the tokens
        var previousBalanceTo = balanceOfAt(_to, block.number);
        require(previousBalanceTo + _amount >= previousBalanceTo); // Check for overflow
        updateValueAtNow(balances[_to], previousBalanceTo + _amount);
        // An event to make the transfer easy to find on the blockchain
        Transfer(_from, _to, _amount);
        return true;
    }

    /// @param _owner The address that's balance is being requested
    /// @return The balance of `_owner` at the current block
    function balanceOf(address _owner) public constant returns (uint256 balance) {
        return balanceOfAt(_owner, block.number);
    }

    /// @notice `msg.sender` approves `_spender` to spend `_amount` tokens on
    ///  its behalf. This is a modified version of the ERC20 approve function
    ///  to be a little bit safer
    /// @param _spender The address of the account able to transfer the tokens
    /// @param _amount The amount of tokens to be approved for transfer
    /// @return True if the approval was successful
    function approve(address _spender, uint256 _amount) public returns (bool success) {
        require(transfersEnabled);

        // To change the approve amount you first have to reduce the addresses`
        //  allowance to zero by calling `approve(_spender,0)` if it is not
        //  already 0 to mitigate the race condition described here:
        //  https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
        require((_amount == 0) || (allowed[msg.sender][_spender] == 0));

        // Alerts the token controller of the approve function call
        if (isContract(controller)) {
            // Adding the ` == true` makes the linter shut up so...
            require(ITokenController(controller).onApprove(msg.sender, _spender, _amount) == true);
        }

        allowed[msg.sender][_spender] = _amount;
        Approval(msg.sender, _spender, _amount);
        return true;
    }

    /// @dev This function makes it easy to read the `allowed[]` map
    /// @param _owner The address of the account that owns the token
    /// @param _spender The address of the account able to transfer the tokens
    /// @return Amount of remaining tokens of _owner that _spender is allowed
    ///  to spend
    function allowance(address _owner, address _spender) public constant returns (uint256 remaining) {
        return allowed[_owner][_spender];
    }

    /// @notice `msg.sender` approves `_spender` to send `_amount` tokens on
    ///  its behalf, and then a function is triggered in the contract that is
    ///  being approved, `_spender`. This allows users to use their tokens to
    ///  interact with contracts in one function call instead of two
    /// @param _spender The address of the contract able to transfer the tokens
    /// @param _amount The amount of tokens to be approved for transfer
    /// @return True if the function call was successful
    function approveAndCall(ApproveAndCallFallBack _spender, uint256 _amount, bytes _extraData) public returns (bool success) {
        require(approve(_spender, _amount));

        _spender.receiveApproval(
            msg.sender,
            _amount,
            this,
            _extraData
        );

        return true;
    }

    /// @dev This function makes it easy to get the total number of tokens
    /// @return The total number of tokens
    function totalSupply() public constant returns (uint) {
        return totalSupplyAt(block.number);
    }


////////////////
// Query balance and totalSupply in History
////////////////

    /// @dev Queries the balance of `_owner` at a specific `_blockNumber`
    /// @param _owner The address from which the balance will be retrieved
    /// @param _blockNumber The block number when the balance is queried
    /// @return The balance at `_blockNumber`
    function balanceOfAt(address _owner, uint _blockNumber) public constant returns (uint) {

        // These next few lines are used when the balance of the token is
        //  requested before a check point was ever created for this token, it
        //  requires that the `parentToken.balanceOfAt` be queried at the
        //  genesis block for that token as this contains initial balance of
        //  this token
        if ((balances[_owner].length == 0) || (balances[_owner][0].fromBlock > _blockNumber)) {
            if (address(parentToken) != 0) {
                return parentToken.balanceOfAt(_owner, min(_blockNumber, parentSnapShotBlock));
            } else {
                // Has no parent
                return 0;
            }

        // This will return the expected balance during normal situations
        } else {
            return getValueAt(balances[_owner], _blockNumber);
        }
    }

    /// @notice Total amount of tokens at a specific `_blockNumber`.
    /// @param _blockNumber The block number when the totalSupply is queried
    /// @return The total amount of tokens at `_blockNumber`
    function totalSupplyAt(uint _blockNumber) public constant returns(uint) {

        // These next few lines are used when the totalSupply of the token is
        //  requested before a check point was ever created for this token, it
        //  requires that the `parentToken.totalSupplyAt` be queried at the
        //  genesis block for this token as that contains totalSupply of this
        //  token at this block number.
        if ((totalSupplyHistory.length == 0) || (totalSupplyHistory[0].fromBlock > _blockNumber)) {
            if (address(parentToken) != 0) {
                return parentToken.totalSupplyAt(min(_blockNumber, parentSnapShotBlock));
            } else {
                return 0;
            }

        // This will return the expected totalSupply during normal situations
        } else {
            return getValueAt(totalSupplyHistory, _blockNumber);
        }
    }

////////////////
// Clone Token Method
////////////////

    /// @notice Creates a new clone token with the initial distribution being
    ///  this token at `_snapshotBlock`
    /// @param _cloneTokenName Name of the clone token
    /// @param _cloneDecimalUnits Number of decimals of the smallest unit
    /// @param _cloneTokenSymbol Symbol of the clone token
    /// @param _snapshotBlock Block when the distribution of the parent token is
    ///  copied to set the initial distribution of the new clone token;
    ///  if the block is zero than the actual block, the current block is used
    /// @param _transfersEnabled True if transfers are allowed in the clone
    /// @return The address of the new MiniMeToken Contract
    function createCloneToken(
        string _cloneTokenName,
        uint8 _cloneDecimalUnits,
        string _cloneTokenSymbol,
        uint _snapshotBlock,
        bool _transfersEnabled
    ) public returns(MiniMeToken)
    {
        uint256 snapshot = _snapshotBlock == 0 ? block.number - 1 : _snapshotBlock;

        MiniMeToken cloneToken = tokenFactory.createCloneToken(
            this,
            snapshot,
            _cloneTokenName,
            _cloneDecimalUnits,
            _cloneTokenSymbol,
            _transfersEnabled
        );

        cloneToken.changeController(msg.sender);

        // An event to make the token easy to find on the blockchain
        NewCloneToken(address(cloneToken), snapshot);
        return cloneToken;
    }

////////////////
// Generate and destroy tokens
////////////////

    /// @notice Generates `_amount` tokens that are assigned to `_owner`
    /// @param _owner The address that will be assigned the new tokens
    /// @param _amount The quantity of tokens generated
    /// @return True if the tokens are generated correctly
    function generateTokens(address _owner, uint _amount) onlyController public returns (bool) {
        uint curTotalSupply = totalSupply();
        require(curTotalSupply + _amount >= curTotalSupply); // Check for overflow
        uint previousBalanceTo = balanceOf(_owner);
        require(previousBalanceTo + _amount >= previousBalanceTo); // Check for overflow
        updateValueAtNow(totalSupplyHistory, curTotalSupply + _amount);
        updateValueAtNow(balances[_owner], previousBalanceTo + _amount);
        Transfer(0, _owner, _amount);
        return true;
    }


    /// @notice Burns `_amount` tokens from `_owner`
    /// @param _owner The address that will lose the tokens
    /// @param _amount The quantity of tokens to burn
    /// @return True if the tokens are burned correctly
    function destroyTokens(address _owner, uint _amount) onlyController public returns (bool) {
        uint curTotalSupply = totalSupply();
        require(curTotalSupply >= _amount);
        uint previousBalanceFrom = balanceOf(_owner);
        require(previousBalanceFrom >= _amount);
        updateValueAtNow(totalSupplyHistory, curTotalSupply - _amount);
        updateValueAtNow(balances[_owner], previousBalanceFrom - _amount);
        Transfer(_owner, 0, _amount);
        return true;
    }

////////////////
// Enable tokens transfers
////////////////


    /// @notice Enables token holders to transfer their tokens freely if true
    /// @param _transfersEnabled True if transfers are allowed in the clone
    function enableTransfers(bool _transfersEnabled) onlyController public {
        transfersEnabled = _transfersEnabled;
    }

////////////////
// Internal helper functions to query and set a value in a snapshot array
////////////////

    /// @dev `getValueAt` retrieves the number of tokens at a given block number
    /// @param checkpoints The history of values being queried
    /// @param _block The block number to retrieve the value at
    /// @return The number of tokens being queried
    function getValueAt(Checkpoint[] storage checkpoints, uint _block) constant internal returns (uint) {
        if (checkpoints.length == 0)
            return 0;

        // Shortcut for the actual value
        if (_block >= checkpoints[checkpoints.length-1].fromBlock)
            return checkpoints[checkpoints.length-1].value;
        if (_block < checkpoints[0].fromBlock)
            return 0;

        // Binary search of the value in the array
        uint min = 0;
        uint max = checkpoints.length-1;
        while (max > min) {
            uint mid = (max + min + 1) / 2;
            if (checkpoints[mid].fromBlock<=_block) {
                min = mid;
            } else {
                max = mid-1;
            }
        }
        return checkpoints[min].value;
    }

    /// @dev `updateValueAtNow` used to update the `balances` map and the
    ///  `totalSupplyHistory`
    /// @param checkpoints The history of data being updated
    /// @param _value The new number of tokens
    function updateValueAtNow(Checkpoint[] storage checkpoints, uint _value) internal {
        if ((checkpoints.length == 0) || (checkpoints[checkpoints.length - 1].fromBlock < block.number)) {
            Checkpoint storage newCheckPoint = checkpoints[checkpoints.length++];
            newCheckPoint.fromBlock = uint128(block.number);
            newCheckPoint.value = uint128(_value);
        } else {
            Checkpoint storage oldCheckPoint = checkpoints[checkpoints.length - 1];
            oldCheckPoint.value = uint128(_value);
        }
    }

    /// @dev Internal function to determine if an address is a contract
    /// @param _addr The address being queried
    /// @return True if `_addr` is a contract
    function isContract(address _addr) constant internal returns(bool) {
        uint size;
        if (_addr == 0)
            return false;

        assembly {
            size := extcodesize(_addr)
        }

        return size>0;
    }

    /// @dev Helper function to return a min betwen the two uints
    function min(uint a, uint b) pure internal returns (uint) {
        return a < b ? a : b;
    }

    /// @notice The fallback function: If the contract's controller has not been
    ///  set to 0, then the `proxyPayment` method is called which relays the
    ///  ether and creates tokens as described in the token controller contract
    function () external payable {
        require(isContract(controller));
        // Adding the ` == true` makes the linter shut up so...
        require(ITokenController(controller).proxyPayment.value(msg.value)(msg.sender) == true);
    }

//////////
// Safety Methods
//////////

    /// @notice This method can be used by the controller to extract mistakenly
    ///  sent tokens to this contract.
    /// @param _token The address of the token contract that you want to recover
    ///  set to 0 in case you want to extract ether.
    function claimTokens(address _token) onlyController public {
        if (_token == 0x0) {
            controller.transfer(this.balance);
            return;
        }

        MiniMeToken token = MiniMeToken(_token);
        uint balance = token.balanceOf(this);
        token.transfer(controller, balance);
        ClaimedTokens(_token, controller, balance);
    }

////////////////
// Events
////////////////
    event ClaimedTokens(address indexed _token, address indexed _controller, uint _amount);
    event Transfer(address indexed _from, address indexed _to, uint256 _amount);
    event NewCloneToken(address indexed _cloneToken, uint _snapshotBlock);
    event Approval(
        address indexed _owner,
        address indexed _spender,
        uint256 _amount
        );

}


////////////////
// MiniMeTokenFactory
////////////////

/// @dev This contract is used to generate clone contracts from a contract.
///  In solidity this is the way to create a contract from a contract of the
///  same class
contract MiniMeTokenFactory {

    /// @notice Update the DApp by creating a new token with new functionalities
    ///  the msg.sender becomes the controller of this clone token
    /// @param _parentToken Address of the token being cloned
    /// @param _snapshotBlock Block of the parent token that will
    ///  determine the initial distribution of the clone token
    /// @param _tokenName Name of the new token
    /// @param _decimalUnits Number of decimals of the new token
    /// @param _tokenSymbol Token Symbol for the new token
    /// @param _transfersEnabled If true, tokens will be able to be transferred
    /// @return The address of the new token contract
    function createCloneToken(
        MiniMeToken _parentToken,
        uint _snapshotBlock,
        string _tokenName,
        uint8 _decimalUnits,
        string _tokenSymbol,
        bool _transfersEnabled
    ) public returns (MiniMeToken)
    {
        MiniMeToken newToken = new MiniMeToken(
            this,
            _parentToken,
            _snapshotBlock,
            _tokenName,
            _decimalUnits,
            _tokenSymbol,
            _transfersEnabled
        );

        newToken.changeController(msg.sender);
        return newToken;
    }
}

// File: contracts/TokenManager.sol

/*
 * SPDX-License-Identitifer:    GPL-3.0-or-later
 */

/* solium-disable function-order */

pragma solidity 0.4.24;







contract TokenManager is ITokenController, IForwarder, AragonApp {
    using SafeMath for uint256;

    bytes32 public constant MINT_ROLE = keccak256("MINT_ROLE");
    bytes32 public constant ISSUE_ROLE = keccak256("ISSUE_ROLE");
    bytes32 public constant ASSIGN_ROLE = keccak256("ASSIGN_ROLE");
    bytes32 public constant REVOKE_VESTINGS_ROLE = keccak256("REVOKE_VESTINGS_ROLE");
    bytes32 public constant BURN_ROLE = keccak256("BURN_ROLE");

    uint256 public constant MAX_VESTINGS_PER_ADDRESS = 50;

    string private constant ERROR_CALLER_NOT_TOKEN = "TM_CALLER_NOT_TOKEN";
    string private constant ERROR_NO_VESTING = "TM_NO_VESTING";
    string private constant ERROR_TOKEN_CONTROLLER = "TM_TOKEN_CONTROLLER";
    string private constant ERROR_MINT_RECEIVER_IS_TM = "TM_MINT_RECEIVER_IS_TM";
    string private constant ERROR_VESTING_TO_TM = "TM_VESTING_TO_TM";
    string private constant ERROR_TOO_MANY_VESTINGS = "TM_TOO_MANY_VESTINGS";
    string private constant ERROR_WRONG_CLIFF_DATE = "TM_WRONG_CLIFF_DATE";
    string private constant ERROR_VESTING_NOT_REVOKABLE = "TM_VESTING_NOT_REVOKABLE";
    string private constant ERROR_REVOKE_TRANSFER_FROM_REVERTED = "TM_REVOKE_TRANSFER_FROM_REVERTED";
    string private constant ERROR_CAN_NOT_FORWARD = "TM_CAN_NOT_FORWARD";
    string private constant ERROR_BALANCE_INCREASE_NOT_ALLOWED = "TM_BALANCE_INC_NOT_ALLOWED";
    string private constant ERROR_ASSIGN_TRANSFER_FROM_REVERTED = "TM_ASSIGN_TRANSFER_FROM_REVERTED";

    struct TokenVesting {
        uint256 amount;
        uint64 start;
        uint64 cliff;
        uint64 vesting;
        bool revokable;
    }

    // Note that we COMPLETELY trust this MiniMeToken to not be malicious for proper operation of this contract
    MiniMeToken public token;
    uint256 public maxAccountTokens;

    // We are mimicing an array in the inner mapping, we use a mapping instead to make app upgrade more graceful
    mapping (address => mapping (uint256 => TokenVesting)) internal vestings;
    mapping (address => uint256) public vestingsLengths;

    // Other token specific events can be watched on the token address directly (avoids duplication)
    event NewVesting(address indexed receiver, uint256 vestingId, uint256 amount);
    event RevokeVesting(address indexed receiver, uint256 vestingId, uint256 nonVestedAmount);

    modifier onlyToken() {
        require(msg.sender == address(token), ERROR_CALLER_NOT_TOKEN);
        _;
    }

    modifier vestingExists(address _holder, uint256 _vestingId) {
        // TODO: it's not checking for gaps that may appear because of deletes in revokeVesting function
        require(_vestingId < vestingsLengths[_holder], ERROR_NO_VESTING);
        _;
    }

    /**
    * @notice Initialize Token Manager for `_token.symbol(): string`, whose tokens are `transferable ? 'not' : ''` transferable`_maxAccountTokens > 0 ? ' and limited to a maximum of ' + @tokenAmount(_token, _maxAccountTokens, false) + ' per account' : ''`
    * @param _token MiniMeToken address for the managed token (Token Manager instance must be already set as the token controller)
    * @param _transferable whether the token can be transferred by holders
    * @param _maxAccountTokens Maximum amount of tokens an account can have (0 for infinite tokens)
    */
    function initialize(
        MiniMeToken _token,
        bool _transferable,
        uint256 _maxAccountTokens
    )
        external
        onlyInit
    {
        initialized();

        require(_token.controller() == address(this), ERROR_TOKEN_CONTROLLER);

        token = _token;
        maxAccountTokens = _maxAccountTokens == 0 ? uint256(-1) : _maxAccountTokens;

        if (token.transfersEnabled() != _transferable) {
            token.enableTransfers(_transferable);
        }
    }

    /**
    * @notice Mint `@tokenAmount(self.token(): address, _amount, false)` tokens for `_receiver`
    * @param _receiver The address receiving the tokens, cannot be the Token Manager itself (use `issue()` instead)
    * @param _amount Number of tokens minted
    */
    function mint(address _receiver, uint256 _amount) external authP(MINT_ROLE, arr(_receiver, _amount)) {
        require(_receiver != address(this), ERROR_MINT_RECEIVER_IS_TM);
        _mint(_receiver, _amount);
    }

    /**
    * @notice Mint `@tokenAmount(self.token(): address, _amount, false)` tokens for the Token Manager
    * @param _amount Number of tokens minted
    */
    function issue(uint256 _amount) external authP(ISSUE_ROLE, arr(_amount)) {
        _mint(address(this), _amount);
    }

    /**
    * @notice Assign `@tokenAmount(self.token(): address, _amount, false)` tokens to `_receiver` from the Token Manager's holdings
    * @param _receiver The address receiving the tokens
    * @param _amount Number of tokens transferred
    */
    function assign(address _receiver, uint256 _amount) external authP(ASSIGN_ROLE, arr(_receiver, _amount)) {
        _assign(_receiver, _amount);
    }

    /**
    * @notice Burn `@tokenAmount(self.token(): address, _amount, false)` tokens from `_holder`
    * @param _holder Holder of tokens being burned
    * @param _amount Number of tokens being burned
    */
    function burn(address _holder, uint256 _amount) external authP(BURN_ROLE, arr(_holder, _amount)) {
        // minime.destroyTokens() never returns false, only reverts on failure
        token.destroyTokens(_holder, _amount);
    }

    /**
    * @notice Assign `@tokenAmount(self.token(): address, _amount, false)` tokens to `_receiver` from the Token Manager's holdings with a `_revokable : 'revokable' : ''` vesting starting at `@formatDate(_start)`, cliff at `@formatDate(_cliff)` (first portion of tokens transferable), and completed vesting at `@formatDate(_vested)` (all tokens transferable)
    * @param _receiver The address receiving the tokens, cannot be Token Manager itself
    * @param _amount Number of tokens vested
    * @param _start Date the vesting calculations start
    * @param _cliff Date when the initial portion of tokens are transferable
    * @param _vested Date when all tokens are transferable
    * @param _revokable Whether the vesting can be revoked by the Token Manager
    */
    function assignVested(
        address _receiver,
        uint256 _amount,
        uint64 _start,
        uint64 _cliff,
        uint64 _vested,
        bool _revokable
    )
        external
        authP(ASSIGN_ROLE, arr(_receiver, _amount))
        returns (uint256)
    {
        require(_receiver != address(this), ERROR_VESTING_TO_TM);
        require(vestingsLengths[_receiver] < MAX_VESTINGS_PER_ADDRESS, ERROR_TOO_MANY_VESTINGS);
        require(_start <= _cliff && _cliff <= _vested, ERROR_WRONG_CLIFF_DATE);

        uint256 vestingId = vestingsLengths[_receiver]++;
        vestings[_receiver][vestingId] = TokenVesting(
            _amount,
            _start,
            _cliff,
            _vested,
            _revokable
        );

        _assign(_receiver, _amount);

        emit NewVesting(_receiver, vestingId, _amount);

        return vestingId;
    }

    /**
    * @notice Revoke vesting #`_vestingId` from `_holder`, returning unvested tokens to the Token Manager
    * @param _holder Address whose vesting to revoke
    * @param _vestingId Numeric id of the vesting
    */
    function revokeVesting(address _holder, uint256 _vestingId)
        external
        authP(REVOKE_VESTINGS_ROLE, arr(_holder))
        vestingExists(_holder, _vestingId)
    {
        TokenVesting storage v = vestings[_holder][_vestingId];
        require(v.revokable, ERROR_VESTING_NOT_REVOKABLE);

        uint256 nonVested = _calculateNonVestedTokens(
            v.amount,
            getTimestamp(),
            v.start,
            v.cliff,
            v.vesting
        );

        // To make vestingIds immutable over time, we just zero out the revoked vesting
        // Clearing this out also allows the token transfer back to the Token Manager to succeed
        delete vestings[_holder][_vestingId];

        // transferFrom always works as controller
        // onTransfer hook always allows if transfering to token controller
        require(token.transferFrom(_holder, address(this), nonVested), ERROR_REVOKE_TRANSFER_FROM_REVERTED);

        emit RevokeVesting(_holder, _vestingId, nonVested);
    }

    // ITokenController fns
    // `onTransfer()`, `onApprove()`, and `proxyPayment()` are callbacks from the MiniMe token
    // contract and are only meant to be called through the managed MiniMe token that gets assigned
    // during initialization.

    /*
    * @dev Notifies the controller about a token transfer allowing the controller to decide whether
    *      to allow it or react if desired (only callable from the token).
    *      Initialization check is implicitly provided by `onlyToken()`.
    * @param _from The origin of the transfer
    * @param _to The destination of the transfer
    * @param _amount The amount of the transfer
    * @return False if the controller does not authorize the transfer
    */
    function onTransfer(address _from, address _to, uint256 _amount) external onlyToken returns (bool) {
        return _isBalanceIncreaseAllowed(_to, _amount) && _transferableBalance(_from, getTimestamp()) >= _amount;
    }

    /**
    * @dev Notifies the controller about an approval allowing the controller to react if desired
    *      Initialization check is implicitly provided by `onlyToken()`.
    * @return False if the controller does not authorize the approval
    */
    function onApprove(address, address, uint) external onlyToken returns (bool) {
        return true;
    }

    /**
    * @dev Called when ether is sent to the MiniMe Token contract
    *      Initialization check is implicitly provided by `onlyToken()`.
    * @return True if the ether is accepted, false for it to throw
    */
    function proxyPayment(address) external payable onlyToken returns (bool) {
        return false;
    }

    // Forwarding fns

    function isForwarder() external pure returns (bool) {
        return true;
    }

    /**
    * @notice Execute desired action as a token holder
    * @dev IForwarder interface conformance. Forwards any token holder action.
    * @param _evmScript Script being executed
    */
    function forward(bytes _evmScript) public {
        require(canForward(msg.sender, _evmScript), ERROR_CAN_NOT_FORWARD);
        bytes memory input = new bytes(0); // TODO: Consider input for this

        // Add the managed token to the blacklist to disallow a token holder from executing actions
        // on the token controller's (this contract) behalf
        address[] memory blacklist = new address[](1);
        blacklist[0] = address(token);

        runScript(_evmScript, input, blacklist);
    }

    function canForward(address _sender, bytes) public view returns (bool) {
        return hasInitialized() && token.balanceOf(_sender) > 0;
    }

    // Getter fns

    function getVesting(
        address _recipient,
        uint256 _vestingId
    )
        public
        view
        vestingExists(_recipient, _vestingId)
        returns (
            uint256 amount,
            uint64 start,
            uint64 cliff,
            uint64 vesting,
            bool revokable
        )
    {
        TokenVesting storage tokenVesting = vestings[_recipient][_vestingId];
        amount = tokenVesting.amount;
        start = tokenVesting.start;
        cliff = tokenVesting.cliff;
        vesting = tokenVesting.vesting;
        revokable = tokenVesting.revokable;
    }

    function spendableBalanceOf(address _holder) public view isInitialized returns (uint256) {
        return _transferableBalance(_holder, getTimestamp());
    }

    function transferableBalance(address _holder, uint256 _time) public view isInitialized returns (uint256) {
        return _transferableBalance(_holder, _time);
    }

    /**
    * @dev Disable recovery escape hatch for own token,
    *      as the it has the concept of issuing tokens without assigning them
    */
    function allowRecoverability(address _token) public view returns (bool) {
        return _token != address(token);
    }

    // Internal fns

    function _assign(address _receiver, uint256 _amount) internal {
        require(_isBalanceIncreaseAllowed(_receiver, _amount), ERROR_BALANCE_INCREASE_NOT_ALLOWED);
        // Must use transferFrom() as transfer() does not give the token controller full control
        require(token.transferFrom(address(this), _receiver, _amount), ERROR_ASSIGN_TRANSFER_FROM_REVERTED);
    }

    function _mint(address _receiver, uint256 _amount) internal {
        require(_isBalanceIncreaseAllowed(_receiver, _amount), ERROR_BALANCE_INCREASE_NOT_ALLOWED);
        token.generateTokens(_receiver, _amount); // minime.generateTokens() never returns false
    }

    function _isBalanceIncreaseAllowed(address _receiver, uint256 _inc) internal view returns (bool) {
        // Max balance doesn't apply to the token manager itself
        if (_receiver == address(this)) {
            return true;
        }
        return token.balanceOf(_receiver).add(_inc) <= maxAccountTokens;
    }

    /**
    * @dev Calculate amount of non-vested tokens at a specifc time
    * @param tokens The total amount of tokens vested
    * @param time The time at which to check
    * @param start The date vesting started
    * @param cliff The cliff period
    * @param vested The fully vested date
    * @return The amount of non-vested tokens of a specific grant
    *  transferableTokens
    *   |                         _/--------   vestedTokens rect
    *   |                       _/
    *   |                     _/
    *   |                   _/
    *   |                 _/
    *   |                /
    *   |              .|
    *   |            .  |
    *   |          .    |
    *   |        .      |
    *   |      .        |
    *   |    .          |
    *   +===+===========+---------+----------> time
    *      Start       Cliff    Vested
    */
    function _calculateNonVestedTokens(
        uint256 tokens,
        uint256 time,
        uint256 start,
        uint256 cliff,
        uint256 vested
    )
        private
        pure
        returns (uint256)
    {
        // Shortcuts for before cliff and after vested cases.
        if (time >= vested) {
            return 0;
        }
        if (time < cliff) {
            return tokens;
        }

        // Interpolate all vested tokens.
        // As before cliff the shortcut returns 0, we can just calculate a value
        // in the vesting rect (as shown in above's figure)

        // vestedTokens = tokens * (time - start) / (vested - start)
        // In assignVesting we enforce start <= cliff <= vested
        // Here we shortcut time >= vested and time < cliff,
        // so no division by 0 is possible
        uint256 vestedTokens = tokens.mul(time.sub(start)) / vested.sub(start);

        // tokens - vestedTokens
        return tokens.sub(vestedTokens);
    }

    function _transferableBalance(address _holder, uint256 _time) internal view returns (uint256) {
        uint256 transferable = token.balanceOf(_holder);

        // This check is not strictly necessary for the current version of this contract, as
        // Token Managers now cannot assign vestings to themselves.
        // However, this was a possibility in the past, so in case there were vestings assigned to
        // themselves, this will still return the correct value (entire balance, as the Token
        // Manager does not have a spending limit on its own balance).
        if (_holder != address(this)) {
            uint256 vestingsCount = vestingsLengths[_holder];
            for (uint256 i = 0; i < vestingsCount; i++) {
                TokenVesting storage v = vestings[_holder][i];
                uint256 nonTransferable = _calculateNonVestedTokens(
                    v.amount,
                    _time,
                    v.start,
                    v.cliff,
                    v.vesting
                );
                transferable = transferable.sub(nonTransferable);
            }
        }

        return transferable;
    }
}