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: when a hurricane moves over land , that hurricane will decrease in strength. 
Sentence2: Hurricanes form over the warm tropical water in ocean and die down when they move over land.

Output: land


Input: Consider Input: Sentence1: the force of water against the seed coat causes a root to emerge from a seed. 
Sentence2: Germination depends on the seed coat.

Output: coat


Input: Consider Input: Sentence1: planting trees has a positive impact on an ecosystem. 
Sentence2: Biodiversity encourages a healthier ecosystem.


Output: ecosystem