using System;

​

public class Program

{

    public static void Main()

    {

        while (true)

        {

            Console.WriteLine("===========Calculator===========");

            Console.Write("Enter first number: ");

            int number1 = Int32.Parse(Console.ReadLine());

            Console.Write("Enter second number: ");

            int number2 = Int32.Parse(Console.ReadLine());

            Console.WriteLine("Select an operation form below: ");

            string operation;

            int value = 0;

            while (true)

            {

                Console.WriteLine("1.Addition\n2.Subtraction\n3.Multiplication\n4.Division");

                operation = Console.ReadLine();

                bool exitLoop = false;

                switch (operation)

                {

                    case "1":

                        value = number1 + number2;

                        operation = "sum";

                        exitLoop = true;

                        break;

                    case "2":

                        value = number1 - number2;

                        operation = "difference";

                        exitLoop = true;

                        break;

                    case "3":

                        value = number1 * number2;

                        operation = "product";

                        exitLoop = true;

                        break;

                    case "4":

                        value = number1 / number2;

                        operation = "output";

                        exitLoop = true;

                        break;

                    default:

                        Console.WriteLine("You selected something other than addition");

                        break;

                }

​

                if (exitLoop == true)

                {

                    break;

                }

            }

​

            Console.WriteLine("The " + operation + " is " + value);

            Console.WriteLine("Do you want to terminate application? (Y/N)");

            bool terminate = false;

            while (true)

            {

                string decision = Console.ReadLine();

                if (decision == "y" || decision == "Y")

                {

                    terminate = true;

                    break;

                }

                else if (decision == "n" || decision == "N")

                {

                    terminate = false;

                    break;

                }

                else

                {

                    continue;

                }

            }

​

            Console.WriteLine("\n\n\n");

            if (terminate == true)

            {

                break;

            }

        }

    }

}