You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named [4-[[(3S)-3-carbamoyl-3,4-dihydro-1H-isoquinolin-2-yl]methyl]-2,6-dimethylphenyl] acetate by IUPAC nomenclature, provide its molecular formula.
user
C21H24N2O3
assistant