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 (2S)-1-[(1R)-1-[4-[4-(cyanomethyl)piperazin-1-yl]phenyl]ethyl]pyrrolidine-2-carboxamide is given. What is its corresponding molecular formula?
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C19H27N5O
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