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 Beatles song was also recorded by Peter Sellers?

Answer: the beatles

Question: The Byzantine Empire is the term used since the 19th century to describe the Roman Empire of the Middle Ages, centred on its capital, where?

Answer: byzantine empire

Question: 'Down and Out in Paris and London' was written by which British author?

Answer:
down and out in paris and london