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.

Input: Consider Input: Sentence1: natural magnetism is used for pointing north by a compass. 
Sentence2: For the ordinary compass, align to the North direction.

Output: north


Input: Consider Input: Sentence1: Macroevolution is more than repeated rounds of microevolution. 
Sentence2: evolution over geologic time above the level of the species is more than repeated rounds of microevolution.

Output: microevolution


Input: Consider Input: Sentence1: a seismometer is used to measure the strength or magnitude of an earthquake. 
Sentence2: A seismometer measures the intensity of the shaking of earthquakes.


Output: measure