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

Example Input: Which group of the 1970's featured Tony Iommi on guitar, Geezer Butler on bass and Bill Ward on drums?
Example Output: geezer butler

Example Input: Joseph Addison and Richard Steele founded (in 1711), and Boris Johnson edited, which British magazine?
Example Output: boris johnson

Example Input: What activity is the subject of the movie Bring it On?
Example Output:
bring it on