You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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N-[(2-chlorophenyl)methyl]-2-[(2R)-2-(2,3-dihydro-1,4-benzodioxin-6-yl)pyrrolidin-1-yl]acetamide is the IUPAC name of a molecule. Please give its molecular formula.
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C21H23ClN2O3
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