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: friction is used for stopping a vehicle by brakes. 
Sentence2: friction is used for stopping a car by brakes.

Output: brakes


Input: Consider Input: Sentence1: Mangoes are propagated vegetatively and by seeds. 
Sentence2: animals propagate mangoes.

Output: Mangoes


Input: Consider Input: Sentence1: Small engines, such as in lawn mowers, pollute at a high rate. 
Sentence2: converting gasoline into motion cause pollution.


Output: pollute