You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
diethyl 4-[(3E)-4,8-dimethylnona-3,7-dienyl]-3,6-dihydropyridazine-1,2-dicarboxylate The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H34N2O4
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