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:
the sunflower ("helianthus annuus") is a living annual plant in the family asteraceae, with a large flower head ("capitulum").

Ex Output:
sunflower


Ex Input:
two-minute warning is a disaster movie from 1976.

Ex Output:

two-minute warning