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: All photos are digital images. 
Sentence2: satellites are used to take photos from space.

Output: photos


Input: Consider Input: Sentence1: Organisms cluster around hydrothermal vents in the ocean floor. 
Sentence2: vents on the ocean floor are powered by heat.

Output: vents


Input: Consider Input: Sentence1: The inner planet is so close to its star that it's too hot. 
Sentence2: if a planet is too close to its star it cannot sustain life.


Output: close