You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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1-[[(2S)-1-[(1S)-1-(3-chloro-4-methoxyphenyl)ethyl]pyrrolidin-2-yl]methyl]-1,2,4-triazole is the IUPAC name of a molecule. Please give its molecular formula.
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C16H21ClN4O
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