instruction:
Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
question:
Who succeeded Jon Pertwee as Doctor Who?
answer:
doctor who


question:
The most northerly part of mainland Australia is in which state?
answer:
australia


question:
Billycock, Wideawake, Gibus and Mitre all types of what?
answer:

bowler hat