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: Distance is measured in meters the SI unit of distance. 
Sentence2: The SI unit of distance is in meters.

Ex Output:
SI


Ex Input:
Sentence1: Faster metabolism means more calories consumed, and usually, weight loss. 
Sentence2: mammals generate heat by consuming calories.

Ex Output:
calories


Ex Input:
Sentence1: when water freezes , that water expands. 
Sentence2: When water freezes it expands and will usually cause damage.

Ex Output:

expands