You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-(3,3-dimethylbut-1-en-2-yl)-5-[3-(7-pyridin-4-yl-3H-imidazo[4,5-c]pyridin-2-yl)-1H-pyrazolo[4,3-b]pyridin-5-yl]pyridin-3-amine is the IUPAC name of a molecule. Please give its molecular formula.
user
C28H25N9
assistant