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: All life relies on a relatively narrow range of pH, or acidity. 
Sentence2: humans rely on a relatively narrow range of acidity.

Ex Output:
acidity


Ex Input:
Sentence1: Carpools and vanpools can save time. 
Sentence2: vanpools decrease the amount of cars used to travel to a place.

Ex Output:
vanpools


Ex Input:
Sentence1: nerves can be used to feel heat and pressure on the skin. 
Sentence2: Nerves can feel heat and pressure on the epidermis.

Ex Output:

feel