using System;

public class Program

{

    public static void Main()

    {

        do

        {

        Console.WriteLine("x=");

        string str = Console.ReadLine();

        if( str== "exit")

        break;

​

        int x = Convert.ToInt32(str);

        Console.WriteLine("y=");

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

        var sum = x+y;

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

    }while(true);

}

}