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: riding a bike does not cause pollution. 
Sentence2: riding a bike does not release particles.

Output: bike


Input: Consider Input: Sentence1: adding salt to a solid decreases the freezing point of that solid. 
Sentence2: Water density decreases with temperature and increases with salt content.

Output: decreases


Input: Consider Input: Sentence1: Flight enables many insects to move quickly away from predators. 
Sentence2: insects generally have two pairs of wings to move quickly away from predators.


Output: away