You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named N-[[1-(3-tert-butyl-[1,2,4]triazolo[4,3-b]pyridazin-6-yl)azetidin-3-yl]methyl]pyrazolo[1,5-a]pyrazin-4-amine by IUPAC nomenclature, provide its molecular formula.
user
C19H23N9
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