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

Example Input: In which country are the Angel Falls, or Kerepakupai Ven?
Example Output: angel falls

Example Input: In which city could you visit the Anne Frank House?
Example Output: anne frank house

Example Input: Which novel did Charles Dickens leave unfinished upon his death in 1870?
Example Output:
charles dickens