Generate an overlapping word between the given two sentences. When you find the overlapping words, they don't have to match exactly, e.g., "survival" and "survive" are valid overlapping words. Little words like "the" or "of" don't count! You must generate significant words which are not the stop words.

Ex Input:
Sentence1: Most mammals have hair, or fur, covering their body.
Sentence2: Most mammals have a body covering for keeping warm.

Ex Output:
body

Ex Input:
Sentence1: Secondary accidents are a major problem under driving conditions of reduced visibility.
Sentence2: Bad weather increases the risk of car accidents.

Ex Output:
Secondary

Ex Input:
Sentence1: Sweat glands produce more sweat.
Sentence2: When the body is hot, something coming from a gland is produced to cool the body.

Ex Output:
glands