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: Mitosis is cell division. 
Sentence2: mitosis often causes growth.

Output: Mitosis


Input: Consider Input: Sentence1: Leaves make food for the plant. 
Sentence2: Some producers have leaves to help use energy and inorganic molecules.

Output: Leaves


Input: Consider Input: Sentence1: Organisms that live in marine biomes must be adapted to the salt in the water. 
Sentence2: Estuaries display characteristics of both marine and freshwater biomes.


Output: biomes