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 country are the Angel Falls, or Kerepakupai Ven?

Ex Output:
angel falls

Ex Input:
Which four letter word beginning with 'F' is a white crumbly Greek cheese, made from sheep's or goats milk and cured in brine?

Ex Output:
sheep

Ex Input:
Bert and Ernie are the names of the policeman and the taxi driver in which Frank Capra film?

Ex Output:
frank capra