You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule N-[(2R,3S,4R,5R,6R)-5-hydroxy-6-(hydroxymethyl)-2-phenylmethoxy-4-[(2S,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]sulfanyloxan-3-yl]acetamide into molecular formula.
user
C21H31NO9S
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