```\ncontract WFTMUnwrapper {\n address constant wftm = 0x21be370D5312f44cB42ce377BC9b8a0cEF1A4C83;\n\n receive() external payable {}\n\n /\*\*\n \* @notice Convert WFTM to FTM and transfer to msg.sender\n \* @dev msg.sender needs to send WFTM before calling this withdraw\n \* @param \_amount amount to withdraw.\n \*/\n function withdraw(uint256 \_amount) external {\n IWETH(wftm).withdraw(\_amount);\n (bool sent, ) = msg.sender.call{ value: \_amount }("");\n require(sent, "Failed to send FTM");\n }\n}\n```\n