You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule 2-(2-chloro-4-methoxyphenyl)-N-[2-(1-methylpyrrolo[2,3-b]pyridin-3-yl)ethyl]acetamide into molecular formula.
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C19H20ClN3O2
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