You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Under IUPAC nomenclature, a molecule named 6-chloro-1-pentyl-7-(phenylmethoxyiminomethyl)-3H-imidazo[4,5-b]pyridin-2-one is given. What is its corresponding molecular formula?
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C19H21ClN4O2
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