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: Most fungi get organic compounds from dead organisms. 
Sentence2: Moulds, yeasts, rusts, smuts, mildews, and mushrooms are all types of fungi.

Ex Output:
fungi


Ex Input:
Sentence1: healing requires rest. 
Sentence2: healing requires time.

Ex Output:
healing


Ex Input:
Sentence1: Plants that shed their leaves seasonally each year are called deciduous plants. 
Sentence2: vines shed their leaves seasonally each year.

Ex Output:

each