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: Most soil nutrients are cations. 
Sentence2: decomposition increases the amount of cations in the soil.

Ex Output:
cations


Ex Input:
Sentence1: an animal requires nutrients to grow and heal. 
Sentence2: Microbes can help an animal to grow and heal.

Ex Output:
grow


Ex Input:
Sentence1: Arteries carry blood away from the heart. 
Sentence2: Something that brings blood away from the heart carries oxygen-rich blood.

Ex Output:

away