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: hop and go is a 1943 looney tunes short movie directed by u.s. corporal norman mccabe and released to movie theaters by rko radio pictures.
Example Output: hop and go

Example Input: a rearguard is a part of a military force that protects the main force from attack from the rear.
Example Output: rearguard

Example Input: le theil-en-auge is a commune.
Example Output:
le theil-en-auge