You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named (2S,4aR,6R,7S,8R,8aS)-8-azido-7-hydroxy-2-[(2-iodophenyl)methyl]-6-phenylsulfanyl-4,4a,6,7,8,8a-hexahydropyrano[3,2-d][1,3]dioxine-2-carbonitrile by IUPAC nomenclature, provide its molecular formula.
user
C21H19IN4O4S
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