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.

Ex 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.

Ex Output:
birth


Ex Input:
Sentence1: Microbes are also called bacteria or microorganisms. 
Sentence2: Disease-causing bacteria have a negative impact on the body.

Ex Output:
bacteria


Ex Input:
Sentence1: Eyes detect light, organized into images that fall on the retina. 
Sentence2: Sight is the process of organized images falling on the retina.

Ex Output:

fall