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: Homogeneous mixtures are called solutions. 
Sentence2: A homogenous mixture is formed when one substance dissolves in another.

Ex Output:
Homogeneous


Ex Input:
Sentence1: Batteries are a better source of DC electricity. 
Sentence2: a flashlight requires batteries to produce light.

Ex Output:
Batteries


Ex Input:
Sentence1: Annelids have the amazing capacity to regrow segments that break off. 
Sentence2: Modern examples are jellyfish, flat worms, and annelid worms.

Ex Output:

Annelids