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 (15R,19R)-15-ethyl-1,11-diazapentacyclo[9.6.2.02,7.08,18.015,19]nonadeca-2,4,6,8(18)-tetraen-12-one into its molecular formula.
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C19H22N2O
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