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 N-[[1-[2-[(2-methylphenyl)methylamino]-2-oxoethyl]piperidin-3-yl]methyl]pyrrolidine-2-carboxamide;hydrochloride into molecular formula.
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C21H33ClN4O2
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