test

import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Scanner;
import java.util.stream.Collectors;

public class problem03 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        List<String> books = Arrays.stream(scanner.nextLine().split("\\&")).collect(Collectors.toList());


        String input = scanner.nextLine();

        while (!input.equals("Done")){
            String[] commands = input.split(" \\|\\ ");
            String mainCommand = commands[0];


            switch (mainCommand) {
                case "Add Book":
                    String book = commands[1];
                    if (books.contains(book)) {
                        input = scanner.nextLine();
                        continue;
                    }else {
                        books.add(0, book);
                    }
                    break;
                case "Take Book":
                     book = commands[1];
                    if(books.contains(book)) {
                        books.remove(book);
                    }else {
                        input= scanner.nextLine();
                        continue;
                    }
                    break;
                case "Swap Books":
                    book = commands[1];
                    String book2 = commands[2];
                    if(books.contains(book)&&books.contains(book2)){
                        int indexFirstBook = books.indexOf(book);
                        int indexSecondBook = books.indexOf(book2);
                        Collections.swap(books, indexFirstBook,indexSecondBook);
                    }else {
                        input = scanner.nextLine();
                        continue;
                    }


                    break;
                case "Insert Book":
                    book = commands[1];
                    if(!books.contains(book)) {
                        int lastIndex = books.size();
                        books.add(lastIndex, book);
                    }else {
                        input= scanner.nextLine();
                        continue;
                    }
                    break;
                case "Check Book":
                    int index = Integer.parseInt(commands[1]);
                    if(books.size()-1 >=index){
                        System.out.println(books.get(index));
                    }else {
                        input = scanner.nextLine();
                        continue;
                    }
                    break;
            }

            input=scanner.nextLine();
        }

        System.out.println(String.join(", ",books));
    }
}