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

Input: Consider Input: What was the first British credit card?

Output: credit card


Input: Consider Input: The Church of the Savior on Spilled Blood, built on the site of the assassination of Tsar Alexander II, is in which Russian city?

Output: church of the savior on blood


Input: Consider Input: Which physicist wrote A Brief History of Time?


Output: a brief history of time