You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N,2-dimethyl-5-[[5-methyl-4-[(3-oxo-4H-1,4-benzoxazin-6-yl)amino]pyrimidin-2-yl]amino]benzenesulfonamide is the IUPAC name of a molecule. Please give its molecular formula.
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C21H22N6O4S
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