You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 4-methyl-5-(3-methyl-9H-carbazol-2-yl)-10,14,17,21-tetrazapentacyclo[12.7.0.02,7.08,13.015,20]henicosa-1(21),2(7),3,5,8(13),9,11,15(20),16,18-decaene into its molecular formula.
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C31H21N5
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