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: Polygenic inheritance Polygenic traits are controlled by an unknown number of genes. 
Sentence2: Skin color is inherited from a number of genes.

Ex Output:
genes


Ex Input:
Sentence1: if an animal sweats then that animal 's bodily water decreases. 
Sentence2: When an animal regulates their body temperature by releasing water, their bodily water decreases.

Ex Output:
bodily


Ex Input:
Sentence1: if weather is stormy then there is a greater chance of rain. 
Sentence2: Rain is a wonderful thing, it helps plants grow.

Ex Output:

rain