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

Example Input: The bells were ringing for Chuck Berry when this song made it to No1. His first and only British No. 1. What song?
Example Output: chuck berry

Example Input: The Battle of Poltava in 1709 was a victory by Peter the Great over which state?
Example Output: battle of poltava

Example Input: Which British author co-wrote the script for the 1968 film 'Chitty Chitty Bang Bang'?
Example Output:
chitty chitty bang bang