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: Basically, heat is energy. 
Sentence2: Head hair is especially important in preventing energy loss from the body.

Output: energy


Input: Consider Input: Sentence1: Sponges are filter feeders. 
Sentence2: Hawksbills feed primarily on filter feeders.

Output: feeders


Input: Consider Input: Sentence1: the Earth being tilted on its rotating axis causes seasons. 
Sentence2: The Earth being tilted on its rotating axis causes the weather to change.


Output: Earth