using System;

public class Program

{

    public static void Main()

    {

        var system = true;

        int num01;

        int num02;

        int ans;

        string ansLine = "Your answer is: ";

        char op;

        do {

            // Welcome

            Console.WriteLine("Simple Calculator");     

            //Number inputs

            Console.Write("Input First number: ");

            num01 = Convert.ToInt32(Console.ReadLine());

            Console.Write("Input Second number: ");

            num02 = Convert.ToInt32(Console.ReadLine());

            //Choosing an operator

            Console.Write("add an operator: ");

            op = Convert.ToChar(Console.ReadLine());

            switch (op) {

                case '+' :

                    ans = num01 + num02;

                    Console.WriteLine(ansLine + ans);

                    break;

                case '-' :

                    ans = num01 - num02;

                    Console.WriteLine(ansLine + ans);

                    break;

                case '*' :

                    ans = num01 * num02;

                    Console.WriteLine(ansLine + ans);

                    break;

                case '/' :

                    ans = num01 / num02;

                    Console.WriteLine(ansLine + ans);

                    break;

                default :

                    Console.WriteLine("That is not an operator");

                    break;

            }

        } while (system == true);

}}