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: Aggression is behavior that is intended to cause harm or pain. 
Sentence2: Verbal violence is behavior that is intended to cause harm or pain.

Ex Output:
behavior


Ex Input:
Sentence1: if fossils of a water animal or plant are found in a place then that place used to be covered by water in the past. 
Sentence2: Fossils are the remains of prehistoric life.

Ex Output:
fossils


Ex Input:
Sentence1: Liquid ounces are a measure of volume, and dry pounds are a measure of mass. 
Sentence2: a graduated cylinder is used to measure liquid ounces.

Ex Output:

Liquid