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: Babies that are very large or very small at birth are less likely to survive. 
Sentence2: Babies that are very large or very small at birth are less likely to live.

Ex Output:
Babies


Ex Input:
Sentence1: skin is used for protecting the body from harmful substances. 
Sentence2: Acids are harmful to tissue.

Ex Output:
harmful


Ex Input:
Sentence1: Ribosomes are sites of protein synthesis. 
Sentence2: Molecules of tRNA initiate protein synthesis.

Ex Output:

protein