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

Ex Input:
Which Beatles song was also recorded by Peter Sellers?

Ex Output:
the beatles

Ex Input:
The rivers Axe, Brue, Cary, Parrett, eta, are in which English county?

Ex Output:
castle cary

Ex Input:
In which country was the notorious concentration camp Auschwitz?

Ex Output:
auschwitz concentration camp