You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name [4-(1-methylpyrazolo[3,4-d]pyrimidin-4-yl)piperazin-1-yl]-(3-pyrrol-1-ylphenyl)methanone into its molecular formula.
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C21H21N7O
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