using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Welcome to the addition only caculator.");

        Console.WriteLine("Please enter you numbers and press enter.");

        Console.WriteLine("If you want to exit, type exit and press enter.");

        do

        {

        string str = Console.ReadLine();

            if str == ("exit")

                Console.WriteLine("thank you for using our calculator");

                break;  

            Console.WriteLine("enter your first number here: ");

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

                Console.WriteLine("enter your second number here: ");

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

                int sum = x + y;

            Console.WriteLine($"your sum is {sum}");

        }

        while(true);

            Console.WriteLine("Thank you for using our app.");

    }

}