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.

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

Example Input: "canuck" is a slang term for canadian people.
Example Output: canuck

Example Input: nelsan ellis (november 30, 1977 – july 8, 2017) was an american actor and playwright.
Example Output:
nelsan ellis