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: Macroevolution occurs over geologic time above the level of the species. 
Sentence2: adding new genes with special capability occurs over geologic time above the level of the species.

Output: above


Input: Consider Input: Sentence1: Annelids have the amazing capacity to regrow segments that break off. 
Sentence2: Earthworms can regrow segments that break off.

Output: break


Input: Consider Input: Sentence1: Evolution is the study of living things with time. 
Sentence2: evolution studies characteristics over time.


Output: study