You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the molecule identified by 3,5,6,10,12a-pentahydroxy-6-methyl-4-(methylamino)-1,11,12-trioxo-3,4,4a,5,5a,11a-hexahydro-2H-tetracene-2-carboxamide ?
user
C21H24N2O9
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