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: Flatworms Flatworms or Platyhelminthes include flukes, tapeworms, and turbellarians. 
Sentence2: Tapeworms belong to the phylum Platyhelminthes.

Output: tapeworms


Input: Consider Input: Sentence1: If the skin is painful, seek medical attention. 
Sentence2: If your skin hurts, your touch receptors will sense differences.

Output: skin


Input: Consider Input: Sentence1: Arteries turn into smaller arteries called arterioles. 
Sentence2: arterioles carry oxygen-rich blood.


Output: arterioles