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:
a detritivore (also known as decomposers) is an animal that feeds on dead organisms (living things) and breaks them down into smaller molecules.

Ex Output:
detritivore


Ex Input:
kurt julius isselbacher (september 12, 1925 – july 18, 2019) was a german-born american physician and gastroenterologist.

Ex Output:
kurt julius isselbacher


Ex Input:
o death — also known as o, death, oh death, and conversations with death — is a traditional american folk song.

Ex Output:

o death