Xdb

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

namespace Test_2
{
    class Program
    {
        static void Main(string[] args)
        {
            List<string> names = Console.ReadLine().Split(',').ToList();
            string comand = Console.ReadLine();

            while(comand != "END")
            {

                switch (comand)
                {
                    case "Add visitor":
                        string visitor = Console.ReadLine();
                        names.Add(visitor);
                        break;
                    case "Add visitor on position":
                        string newV = Console.ReadLine();
                        int index = int.Parse(Console.ReadLine());
                        names.Insert(index, newV);
                        break;
                    case "Remove visitor on position":
                        index = int.Parse(Console.ReadLine());
                        names.Remove(names[index]);
                        break;
                    case "Remove last visitor":
                        names.Remove(names[names.Count - 1]);
                        break;
                    case "Remove first visitor":
                        names.Remove(names.First());
                        break;
                }

                comand = Console.ReadLine();

            }

            Console.WriteLine(string.Join(", ", names));

        }
    }
}