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

Ex Input:
Although it was headquartered at Oak Ridge, TN, and the University of Chicago, what was the name of the WWII project that created the atomic bomb?

Ex Output:
nuclear weapon


Ex Input:
The film The Curious Case of Benjamin Button, starring Brad Pitt, is based on a short story by whom?

Ex Output:
the curious case of benjamin button


Ex Input:
Which painter was married to Mexican artist Diego Rivera?

Ex Output:

diego rivera