Definition: 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: Sentence1: If the egg is fertilized, it can implant in the uterus and cause pregnancy. 
Sentence2: pregnancy occurs when sperm swim to an egg inside an archegonium.

pregnancy