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: Genetics is the study of inheritance. 
Sentence2: Pedigrees are useful tools for studying genetics.

Output: Genetics


Input: Consider Input: Sentence1: All sharks are predators. 
Sentence2: hiding can be used for avoiding sharks.

Output: sharks


Input: Consider Input: Sentence1: if an object reflects light toward the eye then that object can be seen. 
Sentence2: by virtue of scattered light objects reflects light toward the eye.


Output: eye