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

'Dookie' and '21st. Century Breakdown' are albums by which American rock band?
21st century breakdown

Cassandra, Grizabella and Skimbleshanks are all characters in which Andrew Lloyd Webber musical?
andrew lloyd webber

Which Irish boxer was nicknamed the Clones Cyclone?

boxing