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 directed the film `Back To The Future`?

SOLUTION: back to the future

PROBLEM: Betty Driver played which role in Coronation Street?

SOLUTION: betty driver

PROBLEM: Buchanan is a major city in which West African country?

SOLUTION:
buchanan