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: Mollusks are invertebrates such as the common snail. 
Sentence2: Another common snail is the decollate snail.

Ex Output:
snail


Ex Input:
Sentence1: Reptile parents provide little if any care to their young. 
Sentence2: lizard parents provide little if any care to their young.

Ex Output:

any