You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[(4-bromophenyl)methyl]-3-chloro-4-(3-chloro-4-methylanilino)pyrrole-2,5-dione The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H13BrCl2N2O2
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