You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-(dimethylamino)-N-[2-[[6-[(5-methylpyridin-2-yl)amino]pyridazin-3-yl]amino]ethyl]benzamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H25N7O
assistant