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:
"god defend new zealand" is one of the national anthems of new zealand.

Ex Output:
god defend new zealand


Ex Input:
zhejiangopterus is a pterosaur that was found in china.

Ex Output:
zhejiangopterus


Ex Input:
lionel scaloni (born 16 may 1978) is an argentine football player.

Ex Output:

lionel scaloni