gistfile1.txt

pragma solidity >=0.4.22 <0.7.0;

/**
 * @title StorageMsg
 * @dev Store & retreive value in a variable
 */
contract StorageMsg {

    uint256 number;

    event NewNum(uint256 indexed newNumber);

    /**
     * @dev Store value in variable
     * @param num value to store
     */
    function store(uint256 num) public {
        number = num;
        emit NewNum(number);
    }

    /**
     * @dev Return value 
     * @return value of 'number'
     */
    function retreive() public view returns (uint256){
        return number;
    }
}