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: Centrioles come in pairs.
Sentence2: Something that comes in pairs are organelles involved in cell division.

Ex Output:
come

Ex Input:
Sentence1: Energy is the fuel for chemical reactions which run the various systems of the body.
Sentence2: running requires fuel for chemical reactions which run the various systems of the body.

Ex Output:
body

Ex Input:
Sentence1: We learned about desert plants and how they adapt themselves to the hot dry desert environment so they can survive.
Sentence2: Desert plants conserve water to survive in the desert.

Ex Output:
desert