static void Main(string[] args)

{

   do

      {

       Console.Write("x = ");

       string str = Console.ReadLine();

      int x = Convert.ToInt32(str);

      Console.Write("y = ");

      int y = Convert.ToInt32(Console.ReadLine());

      int sum = x + y;

      Console.WriteLine("Result: {0}", sum);

      }

     while (true);

}