You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 3-[3-(3,4-dimethoxyphenyl)-5-oxo-4H-1,2,4-triazin-6-yl]-N-(2-methylpropyl)propanamide into its molecular formula.
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C18H24N4O4
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