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: Tree-ring dating the 1700 Cascadia earthquake. 
Sentence2: estimating the age of trees can be used in reviewing earthquake history.

Output: earthquake


Input: Consider Input: Sentence1: if an animal sweats then that animal 's bodily water decreases. 
Sentence2: When an animal regulates their body temperature by releasing water, their bodily water decreases.

Output: bodily


Input: Consider Input: Sentence1: Benzene, like ozone and particulate matter, is a nonthreshold pollutant. 
Sentence2: particulate matter has a negative impact on the environment.


Output: matter