TASK DEFINITION: Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
PROBLEM: Brasilia is the capital but which city in Brazil has the largest population?

SOLUTION: brazil

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

SOLUTION: boxing

PROBLEM: Who wrote the 1984 Booker Prize winning novel 'Hotel Du Lac'?

SOLUTION:
man booker prize