TASK DEFINITION: Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
PROBLEM: Which of these was the title of Bobby Darin's first million selling single?

SOLUTION: bobby darin

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

SOLUTION: ahura mazda

PROBLEM: What is the title of the second novel featuring Sherlock Holmes, by Arthur Conan Doyle?

SOLUTION:
arthur conan doyle