You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 2-[3-[2-[N-[3-(9,9-diphenylfluoren-4-yl)phenyl]-4-(4-naphthalen-2-ylphenyl)anilino]phenyl]phenyl]phenol by IUPAC nomenclature, provide its molecular formula.
user
C71H49NO
assistant