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: Cells are the units of function in living things. 
Sentence2: living things cannot survive without oxygen.

Ex Output:
living


Ex Input:
Sentence1: soil is formed by weathering. 
Sentence2: Something described as loamy is formed by weathering.

Ex Output:
formed


Ex Input:
Sentence1: wind causes erosion. 
Sentence2: Wind can severely damage soils and crops.

Ex Output:

wind