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:
Aldebaran is the brightest star in which constellation?
answer:
aldebaran


question:
Which Carry On film contained the line 'Oh yes colonel, many times, but never with a daffodil'?
answer:

carry on