You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule 4-(4-chlorophenyl)-5-(1,5-dimethyl-6-oxopyridin-3-yl)-2,3-dimethyl-4H-pyrrolo[3,4-c]pyrazol-6-one ?
user
C20H19ClN4O2
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