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: dew is formed when water vapor condenses over night. 
Sentence2: Condensing is a gas turning into a liquid.

Ex Output:
condenses


Ex Input:
Sentence1: Humans have collected and grown mushrooms for food for thousands of years. 
Sentence2: Yeast and mushrooms are types of fungus.

Ex Output:
mushrooms


Ex Input:
Sentence1: Most of the energy a light bulb uses turns into heat. 
Sentence2: The electricity that a light bulb uses to produce light turns into heat.

Ex Output:

heat