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: natural magnetism is used for pointing north by a compass. 
Sentence2: For the ordinary compass, align to the North direction.

Output: north


Input: Consider Input: Sentence1: Viruses contain DNA but not much else. 
Sentence2: viruses contain encoded information but not much else.

Output: Viruses


Input: Consider Input: Sentence1: Genes that are located on the same chromosome are called linked genes. 
Sentence2: Chromosomes are molecules of DNA complexed with proteins.


Output: chromosome