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: microscope is used to see small things by biologists by making them appear bigger. 
Sentence2: Something invented by Leeuwenhoek is used to see small things by biologists by making them appear bigger.

Output: appear


Input: Consider Input: Sentence1: Earthquakes cause massive damage. 
Sentence2: tectonic plates being pushed together causes massive damage.

Output: damage


Input: Consider Input: Sentence1: Sperm and seminal fluid are released into the urethra during sperm transfer to the female. 
Sentence2: Seminal fluid is passed out of the body to the female through the urethra.


Output: female