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.

Ex Input:
Sentence1: Most mammals have hair, or fur, covering their body. 
Sentence2: Most mammals have a body covering for keeping warm.

Ex Output:
body


Ex Input:
Sentence1: measuring the hardness of minerals requires scratching those materials. 
Sentence2: To figure out the hardness of a mineral, the Moh's scale of hardness is used.

Ex Output:
minerals


Ex Input:
Sentence1: Fission takes place when an animal divides into two parts. 
Sentence2: Euglenoids reproduce by dividing into two parts.

Ex Output:

divides