```\n function provideSecret(bytes32 sale, bytes32 secret\_) external {\n  require(sales[sale].set);\n  if      (sha256(abi.encodePacked(secret\_)) == secretHashes[sale].secretHashA) { secretHashes[sale].secretA = secret\_; }\n        else if (sha256(abi.encodePacked(secret\_)) == secretHashes[sale].secretHashB) { secretHashes[sale].secretB = secret\_; }\n        else if (sha256(abi.encodePacked(secret\_)) == secretHashes[sale].secretHashC) { secretHashes[sale].secretC = secret\_; }\n        else if (sha256(abi.encodePacked(secret\_)) == secretHashes[sale].secretHashD) { secretHashes[sale].secretD = secret\_; }\n        else                                                                          { revert(); }\n }\n```\n