instruction:
Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
question:
Which Chuck Berry song is performed by Marty McFly at the end of the film Back to the Future?
answer:
back to the future


question:
Allopurinol is typically prescribed for which illness?
answer:
allopurinol


question:
Which motor car manufacturer produced models called the 'Cerbera' and 'Chimeara'?
answer:

tvr cerbera