TASK DEFINITION: Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
PROBLEM: Who directed the film Black Swan (in ballet)?

SOLUTION: black swan

PROBLEM: In which religion is there one god called Ahura Mazda?

SOLUTION: ahura mazda

PROBLEM: Who had a 2006 hit with Bad Day?

SOLUTION:
bad day