interface UniswapRouter {
    function WETH() external pure returns (address); // Get address for WETH
    function swapExactTokensForTokens(uint, uint, address[] calldata, address, uint) external returns (uint[] memory);
}
function swapExactTokensForTokens(uint, uint, address[] calldata, address, uint) external returns (uint[] memory);

// Get address for WETH