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: an animal requires nutrients to grow and heal. 
Sentence2: Microbes can help an animal to grow and heal.

Output: grow


Input: Consider Input: Sentence1: Most water comes from precipitation. 
Sentence2: aquatic animals require precipitation to survive.

Output: precipitation


Input: Consider Input: Sentence1: Typically, the liquid is water. 
Sentence2: a cactus stem is used for storing liquid.


Output: liquid