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 1-[[8-benzylsulfanyl-4-(1-oxo-1,4-thiazinan-4-yl)pyrimido[5,4-d]pyrimidin-2-yl]-(1-hydroxyethyl)amino]ethanol into its molecular formula.
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C21H26N6O3S2
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