You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(3S)-1-cyclopentyl-5-oxo-N-[[4-(2-oxopyrrolidin-1-yl)phenyl]methyl]pyrrolidine-3-carboxamide The above is the IUPAC name of a molecule. Write its molecular formula.
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C21H27N3O3
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