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

Ex Input:
Ride of the Valkyries is the official quick march of which branch of the British Army?

Ex Output:
british army


Ex Input:
In May 1940, who became British Prime Minister after the resignation of Neville Chamberlain?

Ex Output:
prime minister of the united kingdom


Ex Input:
Daniel Radcliffe is best known for playing which film role?

Ex Output:

daniel radcliffe