You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance 6-[6-(9a-methyl-4aH-carbazol-9-yl)dibenzofuran-2-yl]-7,8-dihydrobenzimidazolo[1,2-a]benzimidazole .
user
C38H28N4O
assistant