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

Ex Output:
flows


Ex Input:
Sentence1: camouflage is used for protection by prey against predators. 
Sentence2: blending is used for protection.

Ex Output:
protection


Ex Input:
Sentence1: a graduated cylinder is used to measure volume of a liquid. 
Sentence2: Students learn to use a graduated cylinder and measure in mL. 2.

Ex Output:

measure