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

Example Input: Chris Martin is the lead vocalist and rhythm guitarist with which group?
Example Output: chris martin

Example Input: Who had a hit album with Back to Bedlam in 2005?
Example Output: back to bedlam

Example Input: Which opera by Borodin features the Polovtsian Dances?
Example Output:
polovtsian dances