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: Many birds perform elaborate courtship dances. 
Sentence2: Many birds perform dances before they mate.

Output: Many


Input: Consider Input: Sentence1: a camera is used for recording images. 
Sentence2: a camera is used for recording binary.

Output: camera


Input: Consider Input: Sentence1: Lake Trout Lake Trout fishing is good in Loonhaunt and Pipestone Lakes. 
Sentence2: Loonhaunt is generally bigger and deeper than ponds.


Output: Loonhaunt


