You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 2-[(2R)-2-[(2S)-1-acetylpyrrolidin-2-yl]pyrrolidin-1-yl]-N-(cyclohexen-1-yl)-N-ethylacetamide into its molecular formula.
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C20H33N3O2
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