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

Ex Input:
Of all the actors who played Doctor Who in the TV series of the same name, who appeared in the most episodes?

Ex Output:
doctor who


Ex Input:
Which Dutchman managed both Newcastle and Chelsea in the 1990s?

Ex Output:
chelsea f.c.


Ex Input:
Chris Martin is the lead singer with which band who had several hits in the 2000s?

Ex Output:

chris martin