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: Hurricanes have wind speeds of at least 74 mph. 
Sentence2: anemometers can measure hurricanes.

Ex Output:
Hurricanes


Ex Input:
Sentence1: Bound and free ribosomes are structurally identical and interchangeable. 
Sentence2: Bound and free structures are in the cytoplasm where proteins are made.

Ex Output:
Bound


Ex Input:
Sentence1: protein is used to repair cells by the human body. 
Sentence2: Cells need protein to live.

Ex Output:

protein