using System;

​

public class MyProgram

{

    private static Random random = new Random();

    public static void Main(String[] args)

    {

        int player;

        int player1;

        int player2;

        int num;

        player1 = 21;

        player2 = 21;

        player = random.Next(2) + 1;

        while (! (player1 <= 0 || player2 <= 0))

        {

            player = random.Next(2) + 1;

            if (player == 1)

            {

                Console.WriteLine("Chose a number between one and three");

                input(out num);

                if (num >= 1 && num <= 3)

                {

                    player1 = player1 - num;

                    player2 = player1;

                    player = 1;

                }

                else

                {

                    Console.WriteLine("Please enter a number between 1 and 3");

                }

            }

            else

            {

                player2 = player2 + random.Next(3) + -3;

                player1 = player2;

                player = 2;

            }

        }

        if (player == 1)

        {

            Console.WriteLine("player1 wins");

        }

        else

        {

            Console.WriteLine("player2 wins");

        }

    }

    // .NET can only read single characters or entire lines from the console.

    // The following functions are designed to help input specific data types.

    private static void input(out double result)

    {

        while (!double.TryParse(Console.ReadLine(), out result));

    }

    private static void input(out int result)

    {

        while (!int.TryParse(Console.ReadLine(), out result));

    }

    private static void input(out Boolean result)

    {

        while (!Boolean.TryParse(Console.ReadLine(), out result));

    }

    private static void input(out string result)

    {

        result = Console.ReadLine();

    }

}

​