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.

Input: Consider Input: Sentence1: wind is used for producing electricity. 
Sentence2: Winds are caused by pressure differences.

Output: wind


Input: Consider Input: Sentence1: disease-causing microbes have a negative impact on the body. 
Sentence2: pathogens have a negative impact on the body.

Output: body


Input: Consider Input: Sentence1: Sponges have specialized cells called collar cells. 
Sentence2: sponges have flagellum.


Output: Sponges