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: disease-causing microbes have a negative impact on the body. 
Sentence2: pathogens have a negative impact on the body.

Ex Output:
body


Ex Input:
Sentence1: All cells share some of the same structures and basic functions. 
Sentence2: Inside the cell is a structure called the nucleus.

Ex Output:
cells


Ex Input:
Sentence1: Fungi have special structures for penetrating a host. 
Sentence2: Mushrooms have special structures for penetrating a host.

Ex Output:

have