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: if an object is black then that object absorbs all visible light.
Sentence2: Something is black if it absorbs visible light and doesn't reflect.

Output: light

Input: Consider Input: Sentence1: Hermit crabs use the shells of dead snails for homes.
Sentence2: Hermits crabs use dead snails shells as their place to live.

Output: Hermit

Input: Consider Input: Sentence1: Fingernails prevent injury by forming protective plates over the ends of the fingers.
Sentence2: For example, the finger is at the distal end of the human arm.
Output: fingers