NullValuesArithmetic

using System;

class NullValuesArithmetic
{
    static void Main()
    {
     int? num = null;
     double? dsum = null;
     Console.WriteLine(num);
     Console.WriteLine(dsum);
     dsum = 3.2;
     num = 1;
     Console.WriteLine(dsum);
     Console.WriteLine(num);

    }
}