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

Example Input: 'Edward Lewis' and 'Vivian Ward' were the principal characters in which popular 1990 film?
Example Output: edward lewis

Example Input: Which sprinter lit the Olympic flame at the 2000 Summer Olympic Games in Australia?
Example Output: 2000 summer olympics

Example Input: 'Smokestack Lightnin' and 'Red Rooster' were originally recorded by which Chicago blues singer?
Example Output:
chicago blues