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

Output: seasons


Input: Consider Input: Sentence1: All sharks are predators. 
Sentence2: hiding can be used for avoiding sharks.

Output: sharks


Input: Consider Input: Sentence1: Mammals took advantage of the extinction of the dinosaurs. 
Sentence2: large animals that roamed the earth were replaced with mammals after their extinction.


Output: Mammals