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

Example Input: Which film was based on the story The Sentinel by Arthur C Clarke?
Example Output: arthur c. clarke

Example Input: In which US state are the Catskill Mountains?
Example Output: catskill mountains

Example Input: What is the title of the 1971 film in which Clint Eastwood plays DJ Dave Garver?
Example Output:
clint eastwood