izpit 2 100%

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

namespace ConsoleApp59
{
    class Program
    {
        static void Main(string[] args)
        {



            List<string> tr = Console.ReadLine().Split(',').ToList();
            while (true)
            {
                string cmd = Console.ReadLine();
                if (cmd== "END")
                {
                    break;
                }
                else if (cmd == "Add visitor")
                {
                    string newtr = Console.ReadLine();
                    tr.Add(newtr);
                }
                else if (cmd == "Remove last visitor")
                {
                    tr.RemoveAt(tr.Count - 1);
                }
                else if (cmd == "Remove first visitor")
                {
                    tr.RemoveAt(0);
                }
                else if (cmd == "Remove visitor on position")
                {
                    int position = int.Parse(Console.ReadLine());
                    tr.RemoveAt(position);
                }
                else if (cmd == "Add visitor on position")
                {
                    string newtr = Console.ReadLine();
                    int position = int.Parse(Console.ReadLine());
                    tr.Insert(position, newtr);
                }

                }
            Console.WriteLine(string.Join(", ", tr));
        }
    }
}