You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named N-methyl-2-[(3S)-1-[[5-(2-methylpropyl)thiophen-2-yl]methyl]pyrrolidin-3-yl]acetamide by IUPAC nomenclature, provide its molecular formula.
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C16H26N2OS
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