You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Can you give the molecular formula of the molecule 3-fluoro-4-(1-formyl-3,4,4a,5,7,7a-hexahydro-2H-pyrrolo[3,4-b]pyridin-6-yl)-9H-carbazole-1-carboxamide ?
user
C21H21FN4O2
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