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: wiring requires an electrical conductor. 
Sentence2: Gold is an excellent conductor of electricity.

Output: conductor


Input: Consider Input: Sentence1: rocks interacting with wind over long periods of time causes weathering. 
Sentence2: When a rock undergoes erosion and weathering, it breaks down to form sediments.

Output: weathering


Input: Consider Input: Sentence1: Ground tissue makes up most of the interior of a plant. 
Sentence2: Ferns are one type of seedless plant.


Output: plant