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

Ex Input:
Which major river has its source at the confluence of the rivers Brigach and Breg in the Black Forest?

Ex Output:
breg


Ex Input:
Which race run at Chantilly in June is often referred to as the French Derby?

Ex Output:
chantilly racecourse


Ex Input:
Who plays Boycie in Fools and Horses?

Ex Output:

boycie