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: Carpools and vanpools can save time. 
Sentence2: vanpools decrease the amount of cars used to travel to a place.

Output: vanpools


Input: Consider Input: Sentence1: if a habitat can no longer support animals then those animals will move to another area. 
Sentence2: Each species of animal is unique.

Output: animals


Input: Consider Input: Sentence1: Pollination is the fertilization step in the sexual reproduction of plants. 
Sentence2: Bees are absolutely essential for pollination.


Output: Pollination