03. School Library_mid_exam_2022

# 03. School Library , Mid Exam Fundamentals Python June.2022


books = input().split('&')
command = input()

while not command == 'Done':
    details = command.split(' | ')
    if details[0] == 'Add Book':
        name = details[1]
        if name not in books:
            books.insert(0, name)

    elif details[0] == 'Take Book':
        name = details[1]
        if name in books:
            books.remove(name)

    elif details[0] == 'Swap Books':
        name1 = details[1]
        name2 = details[2]
        if (name1 in books) and (name2 in books):
            index1 = books.index(name1)
            index2 = books.index(name2)
            books[index1], books[index2] = books[index2], books[index1]

    elif details[0] == 'Insert Book':
        insert_name = details[1]
        if insert_name not in books:
            books.append(insert_name)

    elif details[0] == 'Check Book':
        index = int(details[1])
        if 0 <= index < len(books):
            print(books[index])

    command = input()
print(*books, sep=", ")