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

Example Input: Who directed the film Black Swan (in ballet)?
Example Output: black swan

Example Input: Who played 'Emma Peel' in the 1998 film 'The Avengers'?
Example Output: the avengers

Example Input: Who directed the films Mississippi Burning, Evita and Angela's Ashes?
Example Output:
angela's ashes