You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name N-[4-[4-[4-(3,5-dimethylphenyl)phenyl]phenyl]phenyl]-N-(9,9'-spirobi[fluorene]-2-yl)-9,9'-spirobi[fluorene]-2-amine into its molecular formula.
user
C76H51N
assistant