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: Most copepods feed on phytoplankton. 
Sentence2: most copepods feed on bacteria and algae that use sunlight to make food.

Output: copepods


Input: Consider Input: Sentence1: After a seed is planted it is watered. 
Sentence2: seeds need water.

Output: seed


Input: Consider Input: Sentence1: Adolescence begins with puberty. 
Sentence2: the last stage of life before adulthood begins with puberty.


Output: begins