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: Without light there is no sense of vision. 
Sentence2: Glass causes a sense of vision.

Output: sense


Input: Consider Input: Sentence1: An astronaut is a scientist who is a space explorer. 
Sentence2: Space explorers require preserved food for long flights.

Output: explorer


Input: Consider Input: Sentence1: Male gametes are sperm. 
Sentence2: male gametes are released into the surrounding water through the osculum.


Output: Male