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 is the only Avril Lavigne song to have reached No.1 in the US Billboard Chart?

Output: avril lavigne


Input: Consider Input: In America, as what was Bill Shoemaker famous?

Output: bill shoemaker


Input: Consider Input: General Gordon, Michelangelo and Cardinal Richelieu have all been played on screen by which actor?


Output: cardinal richelieu