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:
Who composed Air on the G String?

Ex Output:
air on the g string


Ex Input:
Who wrote the 1948 play 'The Browning Version'?

Ex Output:

the browning version