rock paper scissors csharp

                
                        using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Do you choose rock,paper or scissors");
            string userChoice = Console.ReadLine();

            Random r = new Random();
            int computerChoice = r.Next(4);

                if (computerChoice == 1)
                {
                    if (userChoice == "rock")
                    {
                        Console.WriteLine("The computer chose rock");
                        Console.WriteLine("It is a tie ");                     
                    }
                    else if (userChoice == "paper")
                    {
                        Console.WriteLine("The computer chose paper");
                        Console.WriteLine("It is a tie ");

                    }
                    else if (userChoice == "scissors")
                    {
                        Console.WriteLine("The computer chose scissors");
                        Console.WriteLine("It is a tie ");
                    }
                    else
                    {
                        Console.WriteLine("You must choose rock,paper or scissors!");

                    }

                }

                else if (computerChoice == 2)
                {
                    if (userChoice == "rock")
                    {
                        Console.WriteLine("The computer chose paper");
                        Console.WriteLine("Sorry you lose,paper beat rock");

                    }
                    else if (userChoice == "paper")
                    {
                        Console.WriteLine("The computer chose scissors");
                        Console.WriteLine("Sorry you lose,scissors beat paper ");

                    }
                    else if (userChoice == "scissors")
                    {
                        Console.WriteLine("The computer chose rock");
                        Console.WriteLine("Sorry you lose,rock beats scissors");                       
                    }
                    else
                    {
                        Console.WriteLine("You must choose rock,paper or scissors!");        
                    }
                }
                else if (computerChoice == 3)
                {
                    if (userChoice == "rock")
                    {
                        Console.WriteLine("The computer chose scissors");
                        Console.WriteLine("You win,rock beats scissors");

                    }
                    else if (userChoice == "paper")
                    {
                        Console.WriteLine("The computer chose rock");
                        Console.WriteLine("You win,paper beats rock");

                    }
                    else if (userChoice == "scissors")
                    {
                        Console.WriteLine("The computer chose paper");
                        Console.WriteLine("You win,scissors beat paper");

                    }
                    else
                    {
                        Console.WriteLine("You must choose rock,paper or scissors!");

                    }

                }

            Console.ReadLine();
        }
    }
}