pragma solidity 0.5.12; library Math { // based on https://github.com/OpenZeppelin/openzeppelin-contracts/blob/2f9ae975c8bdc5c7f7fa26204896f6c717f07164/contracts/math/Math.sol#L17 function min(uint256 a, uint256 b) internal pure returns (uint256) { return a < b ? a : b; } // based on https://github.com/ethereum/dapp-bin/blob/11f05fc9e3f31a00d57982bc2f65ef2654f1b569/library/math.sol#L28 via https://github.com/ethereum/dapp-bin/pull/50 function sqrt(uint256 x) internal pure returns (uint256 y) { if (x == 0) return 0; else if (x <= 3) return 1; uint256 z = (x + 1) / 2; y = x; while (z < y) { y = z; z = (x / z + z) / 2; } } }