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: Average vehicle speed rises by only 0.3 miles per hour. 
Sentence2: a speedometer measures miles per hour.

Output: hour


Input: Consider Input: Sentence1: a flashlight converts chemical energy into light energy. 
Sentence2: Only as long as there are batteries in the flashlight, the flashlight will function.

Output: flashlight


Input: Consider Input: Sentence1: microbial fuel cells convert chemical energy into electrical energy. 
Sentence2: Bacteria and fungi are the other two classes of microbial pathogens.


Output: microbial