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

Ex Input:
Which former Portuguese African Colony joined the British Commonwealth in 1995?

Ex Output:
commonwealth of nations

Ex Input:
What is the main river of Brazil?

Ex Output:
brazil

Ex Input:
Aside from the Netherlands and Belgium what is the only country in which Dutch is an official language?

Ex Output:
dutch