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: if soil is permeable then water easily flows through that soil. 
Sentence2: if soil is permeable then h2o easily flows through the soil.

Output: flows


Input: Consider Input: Sentence1: Urine leaves the body through a sphincter in the process of urination. 
Sentence2: urine leaves the body upon relaxation of a muscle.

Output: Urine


Input: Consider Input: Sentence1: Bone is less flexible than cartilage but stronger. 
Sentence2: bone is less flexible than chondrocytes.


Output: Bone