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: Basically the process is pretty simple. 
Sentence2: All cells share some of the same structures and simple processes.

Ex Output:
process


Ex Input:
Sentence1: smell is used for finding food by some animals. 
Sentence2: Food includes small rodents and birds.

Ex Output:
food


Ex Input:
Sentence1: Fingernails prevent injury by forming protective plates over the ends of the fingers. 
Sentence2: Fingernail Examination Healthy fingernails are smooth and well shaped.

Ex Output:

Fingernails