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.

Example Input: Sentence1: disease-causing microbes have a negative impact on the body. 
Sentence2: pathogens have a negative impact on the body.
Example Output: body

Example Input: Sentence1: After about a week the larvae leave the nodules and continue to develop into adult worms. 
Sentence2: larvae leave the nodules and continue to transform until having reproductive organs.
Example Output: larvae

Example Input: Sentence1: Urine is the liquid waste product of the body that is excreted by the urinary system. 
Sentence2: Liquid waste is put into the bladder.
Example Output:
liquid