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: To keep cut flowers lasting longer, use a commercial florist preservative such as Floralife. 
Sentence2: Dehydrating food is used to make it last longer.

Ex Output:
lasting


Ex Input:
Sentence1: Instead, the body is covered with a protective shell of bony armor. 
Sentence2: Most mollusks have protective of bony armor.

Ex Output:
armor


Ex Input:
Sentence1: plasma is formed by electrons separating from atoms in stars. 
Sentence2: Most of the plasma is electrons and protons.

Ex Output:

electrons