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: if humans disturb animals in a location then those animals will move to a different location. 
Sentence2: The human being is self-aware.

Ex Output:
humans


Ex Input:
Sentence1: Precipitation falls on the windward side of the mountain range. 
Sentence2: Sheep tend to favour the windward side of a paddock.

Ex Output:
windward


Ex Input:
Sentence1: Trout is an extremely versatile fish. 
Sentence2: trout have a circulatory system with a two-chambered heart.

Ex Output:

Trout