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

Example Input: Which SF author wrote The Day it Rained Forever?
Example Output: the day it rained forever

Example Input: What is the title of the four-episode special of 'Doctor Who', made for the Red Nose Day telethon in the UK, broadcast in March 1999?
Example Output: doctor who

Example Input: The Colossus, one of the seven wonders of the world, was built where?
Example Output:
colossus of rhodes