You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
5-dibenzofuran-4-yl-N,N-bis(4-phenylphenyl)benzimidazolo[1,2-a]benzimidazol-2-amine is the IUPAC name of a molecule. Please give its molecular formula.
user
C49H32N4O
assistant