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 major Atlantic hurricanes start as small disturbances moving westward off Africa. 
Sentence2: When something that starts as a small disturbance moving westward off Africa then moves over land, it will decrease in strength.

Ex Output:
Africa


Ex Input:
Sentence1: the emission of sulfur dioxide causes acid rain. 
Sentence2: Sulfur dioxide emissions causes soil nutrients to be leached away.

Ex Output:
dioxide


Ex Input:
Sentence1: magnetism can cause objects to repel each other. 
Sentence2: magnetism can cause golf clubs to repel each other.

Ex Output:

can