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

Example Input: Who was the scheming wife of the Roman emperor Claudius?
Example Output: claudius

Example Input: What horse won the 2009 Grand National?
Example Output: 2009 grand national

Example Input: What is the word for the point on the Earth's surface that is directly above the point where an earthquake or underground explosion originates?
Example Output:
earthquake