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: Most water comes from precipitation. 
Sentence2: aquatic animals require precipitation to survive.

Output: precipitation


Input: Consider Input: Sentence1: adding salt to a solid decreases the freezing point of that solid. 
Sentence2: Water density decreases with temperature and increases with salt content.

Output: decreases


Input: Consider Input: Sentence1: Heating by direct heat is usually too hot. 
Sentence2: Making an object hot causes thermal expansion.


Output: hot