The solution is to return the book as soon as possible. If the book has been lost, you'd better buy the same version of the book for compensation, so that you can pay the processing fee for each book in 5 yuan. If you can't buy it, you can only compensate according to the book price and the regulations of the library.
If you pay the overdue use fee, you can explain the situation to the staff. If you promise to abide by the library lending system in the future, you will reduce it appropriately.