You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 9-[4-(ethylamino)butyl]-8a-methyl-N-(2,2,2-trifluoroethyl)-2,4b-dihydro-1H-fluorene-9-carboxamide into its molecular formula.
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C23H31F3N2O
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