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

Ex Input:
Devil's Tower National Monument in Wyoming, USA features prominently in which landmark 1977 science fiction film?

Ex Output:
devils tower

Ex Input:
Brasilia is the capital but which city in Brazil has the largest population?

Ex Output:
brazil

Ex Input:
Sevastopol, in the Crimea, lies on the shore of which body of water?

Ex Output:
crimea