You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Translate the chemical IUPAC name 4-[(4R,6S)-3,6-dimethyl-7-oxo-1-phenyl-4,8-dihydropyrazolo[3,4-e][1,4]thiazepin-4-yl]benzoic acid into its molecular formula.
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C21H19N3O3S
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