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: Instead, the body is covered with a protective shell of bony armor. 
Sentence2: Most mollusks have protective of bony armor.

Output: armor


Input: Consider Input: Sentence1: a flashlight converts chemical energy into light energy. 
Sentence2: PALight Flashlights are the ultimate personal LED flashlights.

Output: flashlight


Input: Consider Input: Sentence1: Earth 's magnetic patterns are used for finding locations by animals that migrate. 
Sentence2: Earth s rotation and iron core creates a magnetic field much like giant magnet.


Output: magnetic