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: Finally, the fluid in the nephron reaches a collecting duct . 
Sentence2: fluid in the kidneys collect into ducts.

Output: fluid


Input: Consider Input: Sentence1: Landslides Seismic vibration is a common triggering mechanism for landslides. 
Sentence2: Erosion can cause seismic vibrations which are triggering mechanisms.

Output: Seismic


Input: Consider Input: Sentence1: Babies that are very large or very small at birth are less likely to survive. 
Sentence2: Babies with microsomia are less likely to survive.


Output: are