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: dew is formed when water vapor condenses over night. 
Sentence2: When water vapor condenses overnight, the temperature has reached the dew point.

Ex Output:
condenses


Ex Input:
Sentence1: heavy rains cause flooding. 
Sentence2: Heavy rains cause much of the hurricane damage.

Ex Output:

heavy