You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Under IUPAC nomenclature, a molecule named (4S)-1-methyl-4-[(4-phenyl-5-thiophen-3-ylimidazol-1-yl)methyl]pyrrolidin-2-one is given. What is its corresponding molecular formula?
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C19H19N3OS
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