You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 1-[4-(difluoromethoxy)phenyl]-1-methyl-2-[4-methyl-6-[methyl(pyridin-3-yl)amino]pyrimidin-2-yl]guanidine into its molecular formula.
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C20H21F2N7O
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