You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Provide the molecular formula for the IUPAC named substance (1R)-1-[4-(1,3,4,6,7,8,9,9a-octahydropyrido[1,2-a]pyrazin-2-yl)-3-bromophenyl]ethanol .
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C16H23BrN2O
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