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

Example input: Who was the first American President?
Example output: president of the united states
Example explanation: The question talks about the president of the USA.
Q: Danny O'Donoghue was a judge on the TV show 'The Voice'; he is the singer with which group?
A:
danny o'donoghue