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

Output: sugar


Input: Consider Input: Sentence1: Mitosis is cell division. 
Sentence2: Chromosomes are the form of the genetic material of a cell during mitosis.

Output: Mitosis


Input: Consider Input: Sentence1: the color of leaves on deciduous trees usually changes in the autumn season. 
Sentence2: Fall begins as deciduous trees lose their leaves in the autumn season.


Output: autumn