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: All lizards are reptiles. 
Sentence2: Lizards are tetrapod vertebrates that produce amniotic eggs.

Output: lizards


Input: Consider Input: Sentence1: measuring the hardness of minerals requires scratching those materials. 
Sentence2: To figure out the hardness of a mineral, the Moh's scale of hardness is used.

Output: minerals


Input: Consider Input: Sentence1: Most carcinogens cause cancer by producing mutations in DNA. 
Sentence2: Asbestos is a known carcinogen.


Output: carcinogens