You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule 7-(dimethylamino)-1,10,11-trihydroxy-3,12-dioxo-4,4a,5,5a,6,12a-hexahydrotetracene-2-carbonitrile ?
user
C21H20N2O5
assistant