TASK DEFINITION: Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
PROBLEM: Chep Lap Kok airport is located where?

SOLUTION: hong kong international airport

PROBLEM: Which singer provides the voice for Chef in South Park?

SOLUTION: chef

PROBLEM: The Catcher in the Rye?

SOLUTION:
the catcher in the rye