You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name (Z)-N-[(4-chlorophenyl)methyl]-2-cyano-3-(3,4-dihydro-1H-isoquinolin-2-yl)prop-2-enamide into its molecular formula.
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C20H18ClN3O
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