using System;

public class Program

{

    public static void Main()

    {

        double a = 0;

        double b = 0;

        Console.WriteLine("환영하다 to Junnalyn's Calculator"); 

        //"환영하다" read as Hwanyeonghada and it means Welcome in English

        Console.WriteLine("Type + FOR ADDITION");

        Console.WriteLine("Type - FOR SUBTRACTION");

        Console.WriteLine("Type * FOR MULTIPLICATION");

        Console.WriteLine("Type / FOR DIVISION");

        Console.WriteLine("Type % FOR MODULO");

​

        Console.Write("\nSelect Operation: ");

        string userInput = Console.ReadLine();

        Top:

        if (userInput == "+")

        {

            //ADDITION

            Console.WriteLine("You have selected Addition");

            Console.WriteLine("\n");

            Console.Write("First Number: ");

            a = Convert.ToDouble(Console.ReadLine());

            Console.Write("Second Number");

            b = Convert.ToDouble(Console.ReadLine());

            Console.WriteLine("\n");

            Console.WriteLine("Answer: " + (a+b));

            Console.WriteLine("Press Enter to go back");

            Console.ReadLine();

            Console.Clear();

            goto Top;

        }

        else if (userInput == "-")

        {

            //SUBTRACTION

            Console.WriteLine("You have selected Subtraction");

            Console.WriteLine("\n");

            Console.Write("First Number");

            a = Convert.ToDouble(Console.ReadLine());

            Console.Write("Second Number");

            b = Convert.ToDouble(Console.ReadLine());

            Console.WriteLine("/n");

            Console.WriteLine("Answer: " + (a-b));

            Console.WriteLine("Press Enter to go back");

            Console.ReadLine();

            Console.Clear();

            goto Top;

        }

        else if (userInput == "*")

        {

            //MULTIPLICATION

            Console.WriteLine("You have selected Multiplication");

            Console.WriteLine("\n");

            Console.Write("First Number");

            a = Convert.ToDouble(Console.ReadLine());

            Console.Write("Second Number");

            b = Convert.ToDouble(Console.ReadLine());

            Console.WriteLine("\"n");

            Console.WriteLine("Answer: " + (a*b));

            Console.WriteLine("Please Enter to go back");

            Console.WriteLine("\n");

            Console.ReadLine();

            goto Top;

        }

        else if (userInput == "/")

        {

            //DIVISION

            Console.WriteLine("You have selected Division");

            Console.WriteLine("\n");

            Console.Write("First Number: ");

            a = Convert.ToDouble(Console.ReadLine());

            Console.Write("Second Number: ");

            b = Convert.ToDouble(Console.ReadLine());

            Console.WriteLine("\n");

            Console.WriteLine("Answer: " + (a/b));

            Console.WriteLine("Press Enter to go back");

            Console.WriteLine("\n");

            Console.ReadLine();

            goto Top;

        }

        else if (userInput == "%")

        {

            //MODULO

            Console.WriteLine("You have selected Modulo");

            Console.WriteLine("\n");

            Console.Write("First Number: ");

            a = Convert.ToDouble(Console.ReadLine());

            Console.Write("Second Number: ");

            b = Convert.ToDouble(Console.ReadLine());

            Console.WriteLine("\n");

            Console.WriteLine("Answer: " + (a%b));

            Console.WriteLine("Press Enter to go back");

            Console.WriteLine("\n");

            Console.ReadLine();

            goto Top;

        }

        else

        {

            Console.WriteLine("Error");

            Console.WriteLine("Please try again!");

        }

    }}

​

​