You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named lithium;2-bromo-4-tert-butyl-1-(4-tert-butylphenyl)benzene;2-bromo-2',7'-ditert-butyl-9,9'-spirobi[fluorene];2-bromofluoren-9-one;butane;methane by IUPAC nomenclature, provide its molecular formula.
user
C71H76Br3LiO
assistant