You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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2-[(3S)-1-(cyclopentanecarbonyl)pyrrolidin-3-yl]-N,N-diethyl-4-methylpyrimidine-5-carboxamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H30N4O2
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