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 of these was the title of Bobby Darin's first million selling single?

Output: bobby darin

Input: Consider Input: Which US state was the title of a no. 1 hit for the Bee Gees in 1967?

Output: bee gees

Input: Consider Input: Who plays the main villain in 'Die Hard: With A Vengeance'?
Output: die hard with a vengeance