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: Introns are regions that do not code for proteins. 
Sentence2: regions that do not code for proteins are removed by RNA splicing.

Output: code


Input: Consider Input: Sentence1: plant reproduction requires pollination. 
Sentence2: Plant reproduction requires insects and hummingbirds.

Output: plant


Input: Consider Input: Sentence1: a pulley is used for lifting objects. 
Sentence2: Pulley A pulley makes work easier by changing direction of the force applied.


Output: pulley