You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1,4-dimethylpyrazole;methyl 6-chloropyridazine-3-carboxylate;methyl 6-(1-methylpyrazol-4-yl)pyridazine-3-carboxylate The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H23ClN8O4
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