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

[EX Q]: Who wrote '20,000 Leagues Under The Sea'?
[EX A]: 20,000 leagues under the sea

[EX Q]: Which 'brothers' had a number one hit in May 1958 with 'All I Have To Do Is Dream'?
[EX A]: all i have to do is dream

[EX Q]: Who was the victorious general at the battle of Cannae in 216 BC.?
[EX A]:
battle of cannae