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: Streams may start with runoff or water seeping out of a spring. 
Sentence2: Most water comes from precipitation.

Output: water


Input: Consider Input: Sentence1: Precipitation falls on the windward side of the mountain range. 
Sentence2: Sheep tend to favour the windward side of a paddock.

Output: windward


Input: Consider Input: Sentence1: Menopause occurs when menstruation stops occurring, usually in middle adulthood. 
Sentence2: vaginal dryness can occur when menstruation stops.


Output: menstruation