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.

Input: Consider Input: Sentence1: Basically the process is pretty simple. 
Sentence2: All cells share some of the same structures and simple processes.

Output: process


Input: Consider Input: Sentence1: Pregnancy is the carrying of one or more offspring from fertilization until birth. 
Sentence2: An elephant carries their offspring from fertilization until birth, 22 months later.

Output: fertilization


Input: Consider Input: Sentence1: If it is a sensory nerve cell, it can cause the brain to experience pain. 
Sentence2: stimuli can cause the brain to feel pain.


Output: pain