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 example, insulin is a protein hormone. 
Sentence2: Insulin is produced in a part of the cell called the ribosome.

Ex Output:
insulin


Ex Input:
Sentence1: high pressure systems cause clear weather. 
Sentence2: Weather Clear weather usually means good visibility.

Ex Output:
clear


Ex Input:
Sentence1: Producers are organisms that produce food for themselves and other organisms. 
Sentence2: humans can provide food for other organisms.

Ex Output:

food