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

Example Input: Which poem by Keats and novel by Disraeli both have the same title?
Example Output: john keats

Example Input: Who wrote the poem Elegy Written in a Country Churchyard?
Example Output: elegy written in a country churchyard

Example Input: Which major river has its source at the confluence of the rivers Brigach and Breg in the Black Forest?
Example Output:
breg