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 4-(3-chlorophenyl)-N-[2-(pyridin-2-ylmethyl)pyrazol-3-yl]-3,6-dihydro-2H-pyridine-1-carboxamide into its molecular formula.
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C21H20ClN5O
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