You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named [(9S)-5-(2-methylpyridin-4-yl)-1,6,8-triazatricyclo[7.2.1.02,7]dodeca-2(7),3,5-trien-8-yl]-(pyridazin-4-ylamino)methanol by IUPAC nomenclature, provide its molecular formula.
user
C20H21N7O
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