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

Example Input: Who had a 2000 hit with Country Grammar?
Example Output: country grammar

Example Input: Established in 1919, which is the world's oldest surviving airline?
Example Output: airline

Example Input: Who wrote, co-produced and directed the 2009 film 'Avatar'?
Example Output:
film producer