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

Input: Consider Input: Which Chuck Berry song is performed by Marty McFly at the end of the film Back to the Future?

Output: back to the future


Input: Consider Input: What is the name of the astromech droid companion of Anakin Skywalker, Luke Skywalker and Obi-Wan Kenobi in the Star Wars franchise?

Output: droid


Input: Consider Input: Which British playwright wrote the works Absence of War , Racing Demons and Teeth 'N' Smiles ?


Output: the absence of war