Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.

Input: Consider Input: Of all the actors who played Doctor Who in the TV series of the same name, who appeared in the most episodes?

Output: doctor who


Input: Consider Input: Who wrote the 1939 book The Big Sleep?

Output: the big sleep


Input: Consider Input: In what New York neighborhood would one find the Apollo Theater?


Output: apollo theater