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.

Input: Consider Input: yu gamdong (, ?

Output: yu gamdong


Input: Consider Input: bernhard rensch (21 january 1900–4 april 1990) was a german evolutionary biologist, and ornithologist who did field work in indonesia and india.

Output: bernhard rensch


Input: Consider Input: the flag of bosnia and herzegovina has a wide medium blue vertical band on the fly side with a yellow right triangle adjacent the band and the top of the flag.


Output: flag of bosnia and herzegovina