You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
6-bromo-4-methyl-2,4-dihydro-1H-isoquinolin-3-one;8-bromo-4-methyl-2,4-dihydro-1H-isoquinolin-3-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H20Br2N2O2
assistant