Generate a topic word for the given sentence. A topic word is usually the name of a person, place, animal, concept or object the sentence is focusing on.

Ex Input:
euclid's lemma, also called euclid's division lemma or euclid's first theorem, is an important lemma.

Ex Output:
euclid's lemma

Ex Input:
danilo alvim (3 december 1920 16 may 1996) is a former brazilian football player.

Ex Output:
danilo alvim

Ex Input:
university college cork, or ucc for short, is one of the most famous universities in ireland, alongside trinity college dublin.

Ex Output:
university college cork