PresaleSaleBenchmark2.md

    function claimTicketOrBlockTransactionV2(uint256 ticketNumber) external {
        require(ticketNumber < arr.length * 256, "bad ticket");
        uint256 storageOffset;
        uint256 offsetWithin256;
        uint256 localGroup;
        uint256 storedBit;
        unchecked {
            storageOffset = ticketNumber / 256;
            offsetWithin256 = ticketNumber % 256;
        }
        
        localGroup = arr[storageOffset];
 
        storedBit = (localGroup >> offsetWithin256) & uint256(1);
        require(storedBit == 1, "already claimed");
        localGroup = localGroup & ~(uint256(1) << offsetWithin256);

        arr[storageOffset] = localGroup;
    }

Gas cost: 26,740
Execution - transaction cost (21,000): 5,740