You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule (Z)-N-(3-chloro-4-methylphenyl)-2-cyano-3-[4-(cyanomethoxy)-3-ethoxy-5-iodophenyl]prop-2-enamide into molecular formula.
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C21H17ClIN3O3
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