Given the task definition and input, reply with output. In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

Of the three founding celebrity investors of Planet Hollywood whose full names are mentioned, which has the longest last name?, Context: Schwarzenegger was a founding celebrity investor in the Planet Hollywood chain of international theme restaurants (modeled after the Hard Rock Cafe) along with Bruce Willis, Sylvester Stallone and Demi Moore. Schwarzenegger severed his financial ties with the business in early 2000. Schwarzenegger said the company had not had the success he had hoped for, claiming he wanted to focus his attention on "new US global business ventures" and his movie career.
Sylvester Stallone