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: exercise increases a body 's strength. 
Sentence2: Exercise is more than running and lifting.

Output: exercise


Input: Consider Input: Sentence1: Coral reefs provide food and shelter to many ocean organisms. 
Sentence2: Coral Reefs Coral reefs are threatened.

Output: Coral


Input: Consider Input: Sentence1: All sediments originate from the weathering and erosion of older rocks. 
Sentence2: sediment is formed by erosion.


Output: erosion