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 missing: Magnum Force, The Enforcer, Sudden Impact, and The Dead Pool?

Output: sudden impact


Input: Consider Input: What was the last silent film in which Chaplin's little tramp appeared?

Output: chaplin


Input: Consider Input: What is the title of the recent musical based on a book by Ben Elton with the music of Queen?


Output: ben elton