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

Example Input: To which country do the Chatham Islands belong?
Example Output: chatham islands

Example Input: In which famous film did Michael Caine play a character named Charlie Croker?
Example Output: charlie croker

Example Input: Bridgeport is the largest city by population in which US state?
Example Output:
bridgeport, connecticut