You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name [(3R,4S,6R)-6-(3-acetamido-2-oxochromen-7-yl)oxy-5-hydroxy-3-methoxy-2,2-dimethyloxan-4-yl] N-methylcarbamate into its molecular formula.
user
C21H26N2O9
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