school library

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;

namespace ConsoleApp1
{
    class Exam
    {
        static void Main(string[] args)
        {
            List<string> books = Console.ReadLine().Split('&').ToList();

            List<string> command = Console.ReadLine().Split(" | ").ToList();

            while (command[0] != "Done")
            {
                if (command[0] == "Add Book")
                {
                    string item = command[1];

                    if (!books.Contains(item))
                    {
                        books.Insert(0, item);
                    }
                }
                else if (command[0] == "Take Book")
                {
                    string item = command[1];

                    if (books.Contains(item))
                    {
                        books.Remove(item);
                    }
                }
                else if (command[0] == "Insert Book")
                {
                    string item = command[1];

                    books.Add(item);
                }
                else if (command[0] == "Check Book")
                {
                    int index = int.Parse(command[1]);

                    if (index >= 0 && index < books.Count)
                    {
                        string check = books[index];

                        Console.WriteLine(check);
                    }
                }
                else if (command[0] == "Swap Books")
                {
                    string book1 = command[1];
                    string book2 = command[2];

                    if (books.Contains(book1) && books.Contains(book2))
                    {
                        int book1Index = books.IndexOf(book1);
                        int book2Index = books.IndexOf(book2);

                        books[book1Index] = book2;
                        books[book2Index] = book1;
                    }
                }

                command = Console.ReadLine().Split(" | ").ToList();

            }

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