You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Convert the IUPAC name of a molecule 1-(3,4-dichlorophenyl)-N-[3-(4-methyl-1,2,4-triazol-3-yl)phenyl]-2-oxopyrrolidine-3-carboxamide into molecular formula.
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C20H17Cl2N5O2
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