Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.

[Q]: What is the Army equivalent to a Group Captain in the R.A.F.?
[A]: british army


[Q]: To which country do the Chatham Islands belong?
[A]: chatham islands


[Q]: Which Charles Dickens novel has two title characters, both called 'Paul' and a full title that ends with the words: 'Wholesale, Retail and for Exportation'?
[A]:
charles dickens