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

[EX Q]: The Greeks called her Athena, what was the Roman name for this Goddess?
[EX A]: athena

[EX Q]: What is the main river of Brazil?
[EX A]: brazil

[EX Q]: Nadgett, Elijah Pogram and Tom Pinch appear in which Dickens novel?
[EX A]:
charles dickens