You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-(2,2-dimethylpropyl)-3-methyl-5-[(2S)-2-methylpiperidin-1-yl]imidazo[4,5-b]pyridin-2-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H28N4O
assistant