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: Runoff water is wasted water. 
Sentence2: Streams may start with wasted water.

Output: wasted


Input: Consider Input: Sentence1: Babies that are very large or very small at birth are less likely to survive. 
Sentence2: Poor nutrition while in the womb is the major reason why babies are small at birth.

Output: birth


Input: Consider Input: Sentence1: Negative feedback controls insulin secretion by the pancreas. 
Sentence2: techniques used to precisely control the output control insulin secretion.


Output: controls