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

[Q]: Which Beatles song was also recorded by Peter Sellers?
[A]: the beatles


[Q]: The headquarters building of which government agency is known as 'The Doughnut' due to its shape?
[A]: the doughnut


[Q]: Chopin Airport is in which European city?
[A]:
warsaw chopin airport