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: Cancer is a disease in which cells divide out of control. 
Sentence2: Cancer is a disease in which cells grow and divide rapidly.

Output: Cancer


Input: Consider Input: Sentence1: Hermit crabs use the shells of dead snails for homes. 
Sentence2: Hermits crabs use dead snails shells as their place to live.

Output: Hermit


Input: Consider Input: Sentence1: Fluorescent light bulbs use half the electricity of standard bulbs. 
Sentence2: flourescent bulbs use less electric energy.


Output: Fluorescent