You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-methoxy-N-[4-(1,3,3-trimethyl-2-oxoindol-5-yl)-1,3-thiazol-2-yl]benzamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C22H21N3O3S
assistant