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: Carbon cycles quickly between organisms and the atmosphere. 
Sentence2: the atmosphere is essential to all living organisms.

Ex Output:
organisms


Ex Input:
Sentence1: a magnet moving in a coil of copper wire can cause an electric current. 
Sentence2: An electric current forms when a magnet is run through an induction coil.

Ex Output:
current


Ex Input:
Sentence1: Running water is better able to dissolve oxygen and nutrients than standing water. 
Sentence2: running H2O dissolves oxygen better than standing H2O.

Ex Output:

Running