You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 1-[(1aS,2R,7bS)-6-chloro-2-methyl-2,7b-dihydro-1aH-oxireno[2,3-c]quinolin-3-yl]ethanone into its molecular formula.
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C12H12ClNO2
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