You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name (2R)-4-(4-chlorophenyl)sulfonyl-N-(3,4-dichlorophenyl)-2,3-dihydro-1,4-benzoxazine-2-carboxamide into its molecular formula.
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C21H15Cl3N2O4S
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