You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-[4-[5-[3-(5,5,6,8,8-pentamethyl-6,7-dihydronaphthalen-2-yl)phenyl]indolo[2,3-b]carbazol-7-yl]phenyl]-2-phenyl-[1]benzofuro[2,3-d]pyrimidine is the IUPAC name of a molecule. Please give its molecular formula.
user
C61H48N4O
assistant