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: Warm temperatures have helped plant growth and sizing. 
Sentence2: a greenhouse helps  plant growth.

Output: growth


Input: Consider Input: Sentence1: Telephone Telephone calls are expensive. 
Sentence2: Communicating by transmitting sound is expensive.

Output: expensive


Input: Consider Input: Sentence1: Eggs, butter or margarine keep in the cooler as they do in the refrigerator. 
Sentence2: fat that is a solid at room temperature can be kept in the cooler.


Output: cooler