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: a magnet moving in a coil of copper wire can cause an electric current. 
Sentence2: An electric current forms when a magnet is run through an induction coil.

Ex Output:
current


Ex Input:
Sentence1: a seismometer is used to measure the strength or magnitude of an earthquake. 
Sentence2: Seismometer Calibration : Instructions on how to calibrate a homemade seismometer.

Ex Output:
seismometer


Ex Input:
Sentence1: Cell division is how organisms grow and repair themselves. 
Sentence2: Every cell in the body requires protein for normal function.

Ex Output:

Cell