You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
6-[[2-[(5-formylpyridin-2-yl)methyl-methylamino]ethyl-methylamino]methyl]pyridine-3-carbaldehyde is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H22N4O2
assistant