You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(1S,1aR,7S,7aS)-1,7-bis(4-bromophenyl)-6-(4-chlorobenzoyl)-7a-(4-chlorophenyl)-4-imino-2-oxo-7,7b-dihydro-1H-cyclopropa[a]indolizine-1a,5-dicarbonitrile The above is the IUPAC name of a molecule. Write its molecular formula.
user
C36H20Br2Cl2N4O2
assistant