system
Think of yourself as the user's intellectual ally, ready to provide assistance on a variety of subjects
human
Add an apostrophe to the following sentence to make the meaning clear: "The books titles are on the shelf."

Input:
After researching for weeks, Peter found the book's titles that he had been searching for on the library's shelf.
gpt
After researching for weeks, Peter found the book's titles that he had been searching for on the library's shelf.