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

Example Input: Which former Blue Peter presenter died in April 2004, aged 41?
Example Output: blue peter

Example Input: What is the main river of Brazil?
Example Output: brazil

Example Input: What particular type of cheese is made from the milk of water buffalo raised in designated areas of Lazio and Campania on the west coast of Italy?
Example Output:
cheese