Definition: 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: Sentence1: Pedigree A pedigree is a map of the types of hemoglobin in the family tree. 
Sentence2: a map of the types of hemoglobin in the family tree is a useful tool for studying inheritance patterns.

tree