You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[4-[2-(1-adamantyl)phenyl]phenyl]-2,7-ditert-butyl-N-(9,9-dimethylfluoren-3-yl)-4-methylspiro[4,4a-dihydrofluorene-9,9'-fluorene]-2'-amine is the IUPAC name of a molecule. Please give its molecular formula.
user
C71H71N
assistant