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: sonar is used to find the location of an object. 
Sentence2: Surface ships use sonar to locate and track submarines.

Output: location


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: pesticides can cause pollution. 
Sentence2: Pesticides can hurt plant populations.


Output: can