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: Mammals have a layer of fat under the skin to help insulate the body. 
Sentence2: Mammals have a layer of fat under the skin to provide warmth and comfort.

under