You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Translate the chemical IUPAC name 8-chloro-6-(4-chloro-2-fluorophenyl)-10-methyl-3,4-dihydro-2H-pyrazino[1,2-a]indol-1-one into its molecular formula.
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C18H13Cl2FN2O
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