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: if an object is kicked then force is exerted on that object. 
Sentence2: if an object is kicked then a measurement of newtons is exerted on that object.

Output: exerted


Input: Consider Input: Sentence1: Light source is an ultra-bright, unbreakable LED Bulb. 
Sentence2: LEDs convert electricity into light and heat energy.

Output: LED


Input: Consider Input: Sentence1: Adolescence follows the developmental stage of puberty. 
Sentence2: The period after puberty is a time of significant mental, emotional, and social changes.


Output: puberty