You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[[2-(4-bromo-2-methylphenyl)sulfanylacetyl]-methylamino]-N-(2,6-dimethylphenyl)acetamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H23BrN2O2S
assistant