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: Water is essential for all life on Earth. 
Sentence2: H2O is needed for all life on Eartth.

Output: Earth


Input: Consider Input: Sentence1: high pressure systems cause clear weather. 
Sentence2: Weather Clear weather usually means good visibility.

Output: clear


Input: Consider Input: Sentence1: Some pelycosaurs gave rise to a group of animals called therapsids. 
Sentence2: therapsids are animals.


Output: animals