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 country is currently ruled by the Chakri dynasty that has been in power since 1782?

Ex Output:
chakri dynasty


Ex Input:
Who was the only British medal winner at the 2010 Winter Olympics?

Ex Output:

2010 winter olympics