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: Autumn brings the changing of the seasons. 
Sentence2: Earth 's tilt on its rotating axis causes autumn.

Output: Autumn


Input: Consider Input: Sentence1: a switch is used to start the flow of current in an electrical circuit. 
Sentence2: The flow of electrical current powers a light bulb.

Output: current


Input: Consider Input: Sentence1: Plants detect and respond to the daily cycle of light and darkness. 
Sentence2: Potted plants in season include chrysanthemums, daisies and cyclamen.


Output: Plants