house party

using System;
using System.Linq;
using System.Collections.Generic;
using System.Numerics;
using System.Text;

namespace exampreparation
{
    class exam
    {
        static void Main(string[] args)
        {
            int times = int.Parse(Console.ReadLine());

            List<string> isGoing = new List<string>();

            for (int i = 0; i < times; i++)
            {
                List<string> input = Console.ReadLine().Split().ToList();


                if (input.Count == 3)
                {
                    if (isGoing.Contains(input[0]))
                    {

                        Console.WriteLine($"{input[0]} is already in the list!");
                    }
                    else
                    {
                        isGoing.Add(input[0]);
                    }
                }
                else
                {
                    if (isGoing.Contains(input[0]))
                    {

                        isGoing.Remove(input[0]);
                    }
                    else
                    {
                        Console.WriteLine($"{input[0]} is not in the list!");
                    }
                }

            }

            Console.WriteLine(string.Join(Environment.NewLine, isGoing));
        }
    }
}