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: Microbes are also called bacteria or microorganisms. 
Sentence2: Disease-causing bacteria have a negative impact on the body.

Ex Output:
bacteria


Ex Input:
Sentence1: Weather Clear weather usually means good visibility. 
Sentence2: High pressure systems can cause good visibility.

Ex Output:
good


Ex Input:
Sentence1: Fertilization occurs when sperm swim to an egg inside an archegonium. 
Sentence2: Fertilization occurs when sperm swim to an egg inside a flask-shaped organ.

Ex Output:

Fertilization