You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Convert the IUPAC name of a molecule (4S,6R)-4-(2,4-dihydroxyphenyl)-6-(furan-2-yl)-4-(4-methoxyphenyl)-1,3-diazinane-2-thione into molecular formula.
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C21H20N2O4S
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