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: harming an animal species causes that animal 's population to decrease. 
Sentence2: Wild animal populations have decreased drastically, due to both hunting and loss of habitat.

Output: animal


Input: Consider Input: Sentence1: a light bulb is used for seeing in the dark. 
Sentence2: light is required for seeing.

Output: seeing


Input: Consider Input: Sentence1: Plus, our sense of smell is infinitely better. 
Sentence2: Sense of smell impacts an animal's survival.


Output: sense