Amy has 4 bookshelves. The first shelf contains half as many books as the total number of books on the other 3 shelves. The second shelf contains one-third as many books as the total number of books on the other 3 shelves. The third shelf contains one-fourth as many books as the total number of books on the other 3 shelves. The fourth shelf contains 13 books. What is the total number of books on all the four shelves?
