TASK DEFINITION: Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
PROBLEM: Who played Bonnie in the 1967 film `Bonnie And Clyde`?

SOLUTION: bonnie and clyde

PROBLEM: Which boxer was nicknames `The Brown Bomber`?

SOLUTION: boxing

PROBLEM: Which US gangster was released from Alcatraz prison in November 1939?

SOLUTION:
alcatraz federal penitentiary