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 'Coronation Street' character was played for may years by Jean Alexander?

Output: jean alexander


Input: Consider Input: Which 2000 mile-long river enters the sea at the top of the Gulf of California?


Output: california