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: If there is an increase in UV radiation, the risks go up for all types of skin cancer. 
Sentence2: Ozone depletion increases the risks for all types of skin cancer.

Output: all


Input: Consider Input: Sentence1: dropping an object into water causes vibrations in the water. 
Sentence2: Dropping an object into lake causes vibrations.

Output: dropping


Input: Consider Input: Sentence1: Evolution is a change in the characteristics of living things over time. 
Sentence2: On the other hand, the environment causes all living things to adapt.


Output: living