using System;

​

class NullValuesArithmetic

{

    static void Main()

    {

        int? valueInt = null;

        double? valueDouble = null;

        Console.WriteLine(valueInt);

        Console.WriteLine(valueDouble);

        Console.WriteLine(valueInt+2);

        Console.WriteLine(valueDouble + 2);

        Console.WriteLine(valueInt + null);

        Console.WriteLine(valueDouble + null);

    }

}