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: 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: camouflage is used for protection by prey against predators. 
Sentence2: blending is used for protection.

Ex Output:
protection


Ex Input:
Sentence1: Protein Protein is needed for tissue maintenance and repair. 
Sentence2: protein repairs cells.

Ex Output:

Protein