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: 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.

Output: minerals


Input: Consider Input: Sentence1: a mutation in the sex cells of a parent can cause a new trait to appear in the parent 's offspring. 
Sentence2: Traits are initiated by mutation and recombination.

Output: mutation


Input: Consider Input: Sentence1: Microbes are tiny living cells. 
Sentence2: Disease-causing tiny living cells have a negative impact on the body.


Output: cells