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: Fractures heal when osteoclasts form new bone. 
Sentence2: Fractures A fracture is a broken or cracked bone.

Output: Fractures


Input: Consider Input: Sentence1: Bound and free ribosomes are structurally identical and interchangeable. 
Sentence2: Bound and free structures are in the cytoplasm where proteins are made.

Output: Bound


Input: Consider Input: Sentence1: Nephrons are the structural and functional units of the kidneys. 
Sentence2: Nephrons are the structural and functional units of the organ that filters blood.


Output: Nephrons


