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: For instance, glucose is a sugar. 
Sentence2: insulin helps cells take up sugar from the blood.

Ex Output:
sugar


Ex Input:
Sentence1: Contact with infected blood, contaminated needles. 
Sentence2: scraping oneself on an infected needle may cause infection.

Ex Output:
infected


Ex Input:
Sentence1: Milk is a nutritious fluid. 
Sentence2: Milk shakes have milk.

Ex Output:

Milk