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: Incandescent light bulbs use a tungsten filament sealed inside a glass bulb. 
Sentence2: Tungsten filament sealed in a glass bulb is used for seeing in the dark.

tungsten