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: Climate Forests stabilize climate. 
Sentence2: forests stabilize what is generally described in terms of temperature and moisture.

Ex Output:
Forests


Ex Input:
Sentence1: the Earth being tilted on its rotating axis causes seasons. 
Sentence2: the planet's orbit and tilt causes seasons.

Ex Output:
seasons


Ex Input:
Sentence1: Marine dolphins are endangered by fishing nets, speedboats, and pollution. 
Sentence2: dolphins live mainly in shallow coastal waters.

Ex Output:

dolphins