You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name N-(4-dibenzothiophen-2-ylphenyl)-N-[4-(11,11-dimethylbenzo[a]fluoren-6-yl)phenyl]-9,9'-spirobi[fluorene]-2-amine into its molecular formula.
user
C68H45NS
assistant