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

Ex Input:
Who was the first person to sign the American Declaration of Independence?

Ex Output:
united states declaration of independence


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

Ex Output:
brazil


Ex Input:
What country lies to north of the Republic of Chad?

Ex Output:

chad