You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-(4-cyano-2-methoxyphenoxy)-N-[4-(3,4-dimethylphenyl)-1,3-thiazol-2-yl]acetamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H19N3O3S
assistant