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

[EX Q]: Which entertainer uses various names, including Puff Daddy, P. Diddy and Diddy?
[EX A]: p. diddy

[EX Q]: Which group of the 1970's featured Tony Iommi on guitar, Geezer Butler on bass and Bill Ward on drums?
[EX A]: geezer butler

[EX Q]: The film musical, Cabaret was based on the short novel, Goodbye to Berlin, written in the 1930's by which British author?
[EX A]:
goodbye to berlin