You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 2-(2-bromo-4-cyano-6-ethoxyphenoxy)-N-[2-[3-(difluoromethoxy)-4-methoxyphenyl]ethyl]acetamide into its molecular formula.
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C21H21BrF2N2O5
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