You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[(1S,4aS,11R,12R)-3-carbamoyl-4a,7,12-trihydroxy-11-methyl-2,4,5,6-tetraoxo-1,5a,11,11a,12,12a-hexahydrotetracen-1-yl]-trimethylazanium is the IUPAC name of a molecule. Please give its molecular formula.
user
C23H27N2O8+
assistant