You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named N-[4-[(E)-4-cyano-4-(4-ethyl-5-methyl-1,3-thiazol-2-yl)-3-oxobut-1-enyl]phenyl]acetamide by IUPAC nomenclature, provide its molecular formula.
user
C19H19N3O2S
assistant