using System;

public class Program

{

    public static void Main()

    {

        gobak:

    Console.WriteLine("+ ADDITION");

    Console.WriteLine("- SUBTRACION");

    Console.WriteLine("/ DIVISION");

    Console.WriteLine("* MULTIPLICATION");

    Console.WriteLine("% MODULO");

    Console.WriteLine("f FOR COOL FEATURE");

    Console.WriteLine("Select Operator: ");

    string userInput =  Console.ReadLine();

    int num1;

    int nam2;

    int nim32 = 5;

    if (userInput == "+")

    {

        Console.Write("You have Selected Addition");

        Console.WriteLine("Enter First Number: ");

        double num12 = Convert.ToDouble(Console.ReadLine());

        Console.Write("Enter Second Number: ");

        double num2 = Convert.ToDouble(Console.ReadLine());

        Console.WriteLine("Answer: " + (num12 + num2) );

            Console.Write("Press any key to go back: ");

        Console.ReadLine();

        Console.Clear();

        goto gobak;

    }

    else if (userInput == "f" || userInput == "F")

    {

    Console.WriteLine("You selected the cool feature");

        {

        Console.Write("how many rows do you like?: ");

        nim32 = Convert.ToInt32(Console.ReadLine());

        }

        for ( num1 = 0; num1 <= nim32; num1++)

        {

        for (nam2 = 1; nam2 <= (nim32 - num1); nam2++)

            Console.Write(" ");

        for (nam2 = 1; nam2 <= ((2 * num1) - 1); nam2++)

            Console.Write("*");

            Console.WriteLine();

        }

        for (num1 = nim32 - 1; num1 >= 1; num1--)

        {

        for (nam2 = 1; nam2 <= (nim32 - num1); nam2++)

            Console.Write(" ");

        for (nam2 = 1; nam2 <= ((2 * num1) - 1); nam2++)

            Console.Write("*");

           Console.WriteLine();

        }

        {

        Console.WriteLine();

        Console.Write("(Press any key to go back: )");

        Console.ReadLine();

        Console.Clear();

        goto gobak;     

        }

    }   

        else if (userInput == "-")

    {

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

        Console.WriteLine("Enter First Number: ");

        double num12 = Convert.ToDouble(Console.ReadLine());

        Console.Write("Enter Second Number: ");

        double num2 = Convert.ToDouble(Console.ReadLine());

        Console.WriteLine("Answer: " + (num12 - num2) );

            Console.Write("Press any key to go back: ");

        Console.ReadLine();

        Console.Clear();

        goto gobak;

    }

    else if (userInput == "/")

    {

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

        Console.WriteLine("Enter First Number: ");

        double num12 = Convert.ToDouble(Console.ReadLine());

        Console.Write("Enter Second Number: ");

        double num2 = Convert.ToDouble(Console.ReadLine());

        Console.WriteLine("Answer: " + (num12 / num2) );

            Console.Write("Press any key to go back: ");

        Console.ReadLine();

        Console.Clear();

        goto gobak;

    }

    else if (userInput == "*")

    {

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

        Console.WriteLine("Enter First Number: ");

        double num12 = Convert.ToDouble(Console.ReadLine());

        Console.Write("Enter Second Number: ");

        double num2 = Convert.ToDouble(Console.ReadLine());

        Console.WriteLine("Answer: " + (num12 * num2) );

            Console.Write("Press any key to go back: ");

        Console.ReadLine();

        Console.Clear();

        goto gobak;

    }

    else if (userInput == "%")

    {

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

        Console.WriteLine("Enter First Number: ");

        double num12 = Convert.ToDouble(Console.ReadLine());

        Console.Write("Enter Second Number: ");

        double num2 = Convert.ToDouble(Console.ReadLine());

        Console.WriteLine("Answer: " + (num12 % num2));

            Console.Write("Press any key to go back: ");

        Console.ReadLine();

        Console.Clear();

        goto gobak;

    }

    else

    {

       Console.Clear();

       Console.Write("Please Enter Any key to go back: ");

       Console.ReadLine();

        goto gobak;

    }       

    }

}