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: In which war was the Battle of Bunker Hill?

Answer: battle of bunker hill


Question: Which US state was the title of a no. 1 hit for the Bee Gees in 1967?

Answer: bee gees


Question: The Nou Camp Football Stadium is in which Spanish city?

Answer:
spain