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: Landslides Seismic vibration is a common triggering mechanism for landslides. 
Sentence2: Erosion can cause seismic vibrations which are triggering mechanisms.

Ex Output:
Seismic


Ex Input:
Sentence1: Cells are programmed to divide only a set number of times. 
Sentence2: Cells reproduce asexually, by dividing.

Ex Output:
divide


Ex Input:
Sentence1: Yeast reproduce asexually by budding. 
Sentence2: Bread baking fungus reproduce asexually by budding.

Ex Output:

asexually