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:
eosinophil granulocytes, usually called "eosinophils" or "eosinophiles", are granulocyte white blood cells that fight off certain parasites and infections in vertebrates.

Ex Output:
eosinophil granulocyte


Ex Input:
metis is the goddess of wisdom in greek mythology.

Ex Output:
metis


Ex Input:
louis xvii of france (louis charles; 27 march 1785 - 8 june 1795) was the king of france and navarre from 1793 to 1795.

Ex Output:

louis xvii of france