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: What is the largest country in Africa?

Answer: africa


Question: Betty Driver played which role in Coronation Street?

Answer: betty driver


Question: The cast of which Sylvester Stallone and Michael Caine film also included footballers Bobby Moore, John Wark and Ossie Ardilles?

Answer:
sylvester stallone