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: Energy used for heating is the single most commonly used form of energy worldwide. 
Sentence2: Heating buildings is a very common production of energy worldwide.

Energy