You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance 2-(5-acetyl-3-cyano-6-methylpyridin-2-yl)sulfanyl-N-[4-(4-methylphenyl)-1,3-thiazol-2-yl]acetamide .
user
C21H18N4O2S2
assistant