You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N'-(3-chlorophenyl)-5-(4-chlorophenyl)-N-cyano-4-(2-oxopyrrolidin-1-yl)-3,4-dihydropyrazole-2-carboximidamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H18Cl2N6O
assistant