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: Nonmetal elements are far fewer in number. 
Sentence2: There are 17 nonmetals on the periodic table.

Output: Nonmetal


Input: Consider Input: Sentence1: the ovaries are used in reproduction. 
Sentence2: Egg released by the ovary.

Output: ovaries


Input: Consider Input: Sentence1: Examples of gametes are ova and spermatozoa. 
Sentence2: meiosis is the type of cell division that produces ova and spermatozoa.


Output: ova