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

Ex Input:
Whitney Houston's husband Bobby Brown was originally a member of which successful band?

Ex Output:
bobby brown

Ex Input:
Who was Prime Minister of Australia at the outbreak of World War I?

Ex Output:
australia

Ex Input:
What is the name of Liam Gallagher's new band, whose first album is 'Different Gear, Still Speeding'?

Ex Output:
different gear, still speeding