You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Translate the chemical IUPAC name 2-methyl-6-[[5-methyl-1-(2-methylphenyl)pyrazol-4-yl]methyl]-3,5,7,8-tetrahydropyrido[4,3-d]pyrimidin-4-one into its molecular formula.
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C20H23N5O
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