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

Ex Input:
In which range of mountains are the two highest peaks Aconcagua and Ojos Del Salado?

Ex Output:
aconcagua

Ex Input:
Abyssinian, British Longhair and German Rex are all breeds of what?

Ex Output:
british longhair

Ex Input:
Which actor played the second Dr Who?

Ex Output:
doctor who