Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
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Question: Which American actor and singer has joined Amanda Holden as one of the judges on the current series of 'Britain's Got Talent'?

Answer: britain's got talent


Question: Which entertainer uses various names, including Puff Daddy, P. Diddy and Diddy?

Answer: p. diddy


Question: The Battle of Antietam was fought during which war?

Answer:
battle of antietam