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: Boiling water can cause burns. 
Sentence2: heating water can cause burns.

Ex Output:
water


Ex Input:
Sentence1: conserving water can be used for survival in a dry environment. 
Sentence2: conserving water can be used for survival in deserts.

Ex Output:
conserving


Ex Input:
Sentence1: Annelids have the amazing capacity to regrow segments that break off. 
Sentence2: Earthworm Jim the greatest soil munchin' annelid fansite has been re-located.

Ex Output:

Annelids