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

Ex Input:
Which mediaeval author wrote The Canterbury Tales?

Ex Output:
the canterbury tales


Ex Input:
Which group of the 1970's featured Tony Iommi on guitar, Geezer Butler on bass and Bill Ward on drums?

Ex Output:
geezer butler


Ex Input:
Mark Zuckerberg, Eduardo Saverin, Dustin Moskovitz and Chris Hughes developed what online computer application?

Ex Output:

chris hughes