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:
the bumblebee bat ("craseonycteris thonglongyai"), also known as kitti's hog-nosed bat, is an endangered species of bat.

Ex Output:
bumblebee bat

Ex Input:
chiayi city (; taiwanese: ka-gi chhi) is a provincial city of southwestern taiwan province of the republic of china.

Ex Output:
chiayi city

Ex Input:
sonic firestorm is the second studio album by english power metal band dragonforce released through on may 11, 2004.

Ex Output:
sonic firestorm