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

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:
Which form of dementia is named after a German psychiatrist who first described it in 1906?

Ex Output:
dementia


Ex Input:
Whose first husband was Conrad Hilton Jnr., heir to the hotel empire?

Ex Output:

conrad hilton