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

Ex Input:
Which biologist was known as Darwin's Bulldog?

Ex Output:
charles darwin


Ex Input:
Zoey Barkow, Kevin Peyton, Eddie Walzer and Fitch Cooper are all characters in which US television series?

Ex Output:
merritt wever


Ex Input:
Ciara had a hit with 1,2 Step featuring which other artist?

Ex Output:

1, 2 step