You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
9-[3-cyclohexa-1,5-dien-1-yl-5-(cyclohexen-1-yl)phenyl]-6-[9-(9,9-dimethylfluoren-3-yl)-1,2,4a,5,6,9a-hexahydrocarbazol-3-yl]-3,4,4b,5-tetrahydrocarbazole is the IUPAC name of a molecule. Please give its molecular formula.
user
C57H56N2
assistant