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: Crops are plants that are grown for food or other uses. 
Sentence2: insects destroy plants.

Ex Output:
plants


Ex Input:
Sentence1: Ejaculation allows males to reproduce. 
Sentence2: propelling sperm from the epididymes allows males to reproduce.

Ex Output:
allows


Ex Input:
Sentence1: Nephrons are the structural and functional units of the kidneys. 
Sentence2: kidneys contain  a system of blood vessels and tubules.

Ex Output:

kidneys