You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule (3R)-N-[(5-chlorothiophen-2-yl)methyl]-1-[(3S)-1,1-dioxothiolan-3-yl]-N-ethyl-5-oxopyrrolidine-3-carboxamide into molecular formula.
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C16H21ClN2O4S2
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