You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
9-[9-(3-carbazol-9-ylphenyl)carbazol-3-yl]-5-phenyl-[1]benzofuro[3,2-c]carbazole The above is the IUPAC name of a molecule. Write its molecular formula.
user
C54H33N3O
assistant