You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-[3-(4a,9a-dihydrocarbazol-9-yl)-5-(9-phenyl-5,6-dihydrocarbazol-3-yl)phenyl]-9-phenyl-4a,9a-dihydrocarbazole The above is the IUPAC name of a molecule. Write its molecular formula.
user
C54H41N3
assistant