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 major river has its source at the confluence of the rivers Brigach and Breg in the Black Forest?

Output: breg


Input: Consider Input: Grace Anna Goodhue was the wife of which US President?

Output: grace coolidge


Input: Consider Input: Which great composer, composed so many songs between 1815 and 1828 that the Oxford Dictionary of Music doesn't attempt to list them all?


Output: composer