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

Example Input: Basil Rathbone made 14 Sherlock Holmes films. Who played the part of Dr Watson?
Example Output: watson

Example Input: Which BBC current affairs programme, the longest-running in the world, is 60 years old this year ?
Example Output: bbc

Example Input: What is the SI unit of capacitance?
Example Output:
capacitance