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: Telephone Telephone calls are expensive. 
Sentence2: Communicating by transmitting sound is expensive.

Output: expensive


Input: Consider Input: Sentence1: Some herbivores have more than one stomach. 
Sentence2: Camels are an herbivore.

Output: herbivores


Input: Consider Input: Sentence1: Minerals are chemical elements that are essential for body processes. 
Sentence2: Healing is a natural process for the human body.


Output: body