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: Angiosperm sporophyte is dominant. 
Sentence2: Flowers form on angiosperms.

Ex Output:
Angiosperm


Ex Input:
Sentence1: Flies are insects with two wings. 
Sentence2: Flies are arthropods with two wings.

Ex Output:
Flies


Ex Input:
Sentence1: Blood is a fluid connective tissue. 
Sentence2: Blood is pulsed through the body.

Ex Output:

Blood