You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2S)-N,N-dimethyl-2-[methyl-[2-(2-methyl-4-oxoquinolin-1-yl)acetyl]amino]propanamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H23N3O3
assistant