You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[(4aS,6S,8aR)-6-[[2-(3,4-dichlorophenyl)acetyl]amino]-4a-(3-hydroxyphenyl)-2,2-dimethyl-3,4,5,6,7,8-hexahydro-1H-isoquinolin-2-ium-8a-yl] acetate is the IUPAC name of a molecule. Please give its molecular formula.
user
C27H33Cl2N2O4+
assistant