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.

Example Input: Sentence1: Ozone depletion results in higher levels of UV radiation reaching Earth. 
Sentence2: less ozone means more ultraviolet light.
Example Output: Ozone

Example Input: Sentence1: Light is the visible form of electromagnetic energy. 
Sentence2: Electromagnetic energy enters the eye through an opening called the pupil.
Example Output: electromagnetic

Example Input: Sentence1: Tight fitting shoes can increase the pressure on the skin and exacerbates the pain. 
Sentence2: Nerves can be used to feel heat and pain on the skin.
Example Output:
pain