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

Ex Input:
Who composed Air on the G String?

Ex Output:
air on the g string

Ex Input:
'Edward Lewis' and 'Vivian Ward' were the principal characters in which popular 1990 film?

Ex Output:
edward lewis

Ex Input:
Delamere Forest is in which English county?

Ex Output:
delamere forest