FILE: 2024-05-arbitrum-foundation/src/challengeV2/libraries
/EdgeChallengeManagerLib.sol 

 function mandatoryBisectionHeight(uint256 start, uint256 end) internal pure returns (uint256) {
        if (end - start < 2) {
            revert HeightDiffLtTwo(start, end);
        }
        if (end - start == 2) {
            return start + 1;
        }

        uint256 diff = (end - 1) ^ start;
        uint256 mostSignificantSharedBit = UintUtilsLib.mostSignificantBit(diff);
        uint256 mask = type(uint256).max << mostSignificantSharedBit;
        return ((end - 1) & mask);
    }
