MyContract.sol

// SPDX-License-Identifier: GPL-3.0

pragma solidity >=0.7.0 <0.9.0;

contract MyContract {
    // state variable num
    uint256 public num;
  
    // function sets value of variable num equal to _num 
    function setNum(uint256 _num) public returns(uint256) {
        num = _num;
        
        return num;
    }
}