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: Cnidarians are invertebrates such as jellyfish and corals. 
Sentence2: Jellyfish and corals are radial, tentacled animals that live mostly in the seas.

Ex Output:
corals


Ex Input:
Sentence1: Weather today is said to be sunny and clear. 
Sentence2: High pressure systems cause it to be sunny.

Ex Output:
sunny


Ex Input:
Sentence1: Black Holes Black holes are the inevitable conclusion of Einstein's General Theory of Relativity. 
Sentence2: When a high-mass star collapses, it fulfills the inevitable conclusion Einstein's General Theory of relativity.

Ex Output:

Einstein's