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: Chordates have a complete digestive system and a closed circulatory system. 
Sentence2: animals with jaws have a complete digestive system and a closed circulatory system.

Output: circulatory


Input: Consider Input: Sentence1: Most bryophytes are small. 
Sentence2: Most in the same group as mosses are small.

Output: small


Input: Consider Input: Sentence1: hiding can be used for avoiding predators. 
Sentence2: hiding can be used by animals like young birds.


Output: hiding