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

[EX Q]: Charles Bingley was a character in what classic Jane Austen novel?
[EX A]: charles bingley

[EX Q]: Which 20th century British prime minister had the longest surname ?
[EX A]: prime minister of the united kingdom

[EX Q]: Who featured on the 2010 Usher track DJ Got Us Falling in Love Again?
[EX A]:
dj got us fallin' in love