You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[9-(4-methoxyphenyl)-9-phenylfluoren-2-yl]-N-(4-phenylphenyl)spiro[1,9a-dihydrofluorene-9,9'-fluorene]-2-amine The above is the IUPAC name of a molecule. Write its molecular formula.
user
C63H45NO
assistant