You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-methyl-N-[2-[(3S)-3-methyl-3,4-dihydro-1H-isoquinolin-2-yl]-2-oxoethyl]furan-3-carboxamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H20N2O3
assistant