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: Sponges are filter feeders. 
Sentence2: Hawksbills feed primarily on filter feeders.

Output: feeders


Input: Consider Input: Sentence1: Speciation events are thus examples of macroevolution. 
Sentence2: Speciation events occur over geologic time above the level of the species.

Output: Speciation


Input: Consider Input: Sentence1: if seeds stick to the fur of an animal then that seed will be transported by the animal. 
Sentence2: Gelatinous coating helps seeds stick to fur and clothing when wet.


Output: fur