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

Ex Input:
Where is David Cameron's Oxfordshire constituency?

Ex Output:
david cameron


Ex Input:
Which British composer wrote the music used as the theme for Desert Island Discs  He also wrote the Dambusters march and the Knightsbridge march.?

Ex Output:
the dam busters


Ex Input:
In which book of the Bible did David kill Goliath?

Ex Output:

bible