You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name ethyl (6S)-4-methyl-6-[4-(2-methylpropanoylamino)phenyl]-2-oxo-3-propyl-1,6-dihydropyrimidine-5-carboxylate into its molecular formula.
user
C21H29N3O4
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