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

Input: Consider Input: Who directed the film Black Swan (in ballet)?

Output: black swan

Input: Consider Input: Who, as the first chairman of the British Rail Board, infamously directed the huge reduction in railway lines across the UK in the 1960s?

Output: british railways board

Input: Consider Input: What nationality was the pirate Captain Kidd?
Output: william kidd