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.

Input: Consider Input: Sentence1: Lymph is a fluid that leaks out of capillaries into spaces between cells. 
Sentence2: Humans are made up of trillions of cells.

Output: cells


Input: Consider Input: Sentence1: ultraviolet light causes sunburn. 
Sentence2: Sunburn risk is higher at elevation.

Output: sunburn


Input: Consider Input: Sentence1: when a hurricane moves over land , that hurricane will decrease in strength. 
Sentence2: Hurricanes grow strength from warm waters.


Output: strength