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 is the only Avril Lavigne song to have reached No.1 in the US Billboard Chart?

Answer: avril lavigne


Question: Which city has sports teams known as the 'Maple Leafs' and the 'Blue Jays'?

Answer: toronto blue jays


Question: Bohol, Masbate, Luzon and Jolo are all part of which island group?

Answer:
masbate