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: The novels 'The Shipmaster, 'The Iron Ships' and 'The Trade Winds' by Cyril Abraham, are based on which 1970's British tv series?

Answer: cyril abraham

Question: Which RAF base is located on Cyprus?

Answer:
royal air force