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: the ovaries are used in reproduction. 
Sentence2: Unlike most female animals, which have two functioning ovaries, the chicken usually has only one.

Ex Output:
ovaries


Ex Input:
Sentence1: Germination depends on the seed coat. 
Sentence2: the force of water causes germination with the emergence of a root.

Ex Output:
Germination


Ex Input:
Sentence1: Blood is a fluid connective tissue. 
Sentence2: A fluid connective tissue carries oxygen to the brain.

Ex Output:

connective