You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule ethyl 2-[(1,3-dimethyl-2,4-dioxopyrimidine-5-carbonyl)amino]-5-methyl-4-phenylthiophene-3-carboxylate into molecular formula.
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C21H21N3O5S
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