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

Input: Consider Input: What's the name of Doctor Who's home planet ?

Output: doctor who


Input: Consider Input: Which Beatles song was also recorded by Peter Sellers?

Output: the beatles


Input: Consider Input: With its capital at Dusseldorf and its largest city of Cologne, what is the most populous state of Germany?


Output: cologne