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: Without light there is no sense of vision. 
Sentence2: Glass causes a sense of vision.

Ex Output:
sense


Ex Input:
Sentence1: Electrical currents cause magnetic fields. 
Sentence2: Electrical currents can cause objects to repel each other.

Ex Output:
Electrical


Ex Input:
Sentence1: Vesicle transport requires energy, so it is also a form of active transport. 
Sentence2: Synaptic vesicles glutamate transporter 5.

Ex Output:

Vesicle