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: Bacteria and Viruses Bacteria and viruses can cause diseases. 
Sentence2: bacteria can have a negative impact on an organism.

Output: Bacteria


Input: Consider Input: Sentence1: when a river floods , that river deposits soil in flood plains. 
Sentence2: Hurricanes can cause local flooding, flash flooding, or coastal flooding.

Output: flood


Input: Consider Input: Sentence1: Horses are domestic animals. 
Sentence2: horses are multicellular eukaryotes.


Output: Horses