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

Example Input: In which US state would you find the cities of Chesapeake, Roanoke and Fredericksburg?
Example Output: fredericksburg

Example Input: Christopher Eccleston, Kerry Fox and Ewan McGregor played flatmates in which 1994 film?
Example Output: christopher eccleston

Example Input: Which US president was shot five days after the end of the American Civil War?
Example Output:
american civil war