You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-methyl-N-[[2-(4-methylphenyl)-1,3-thiazol-4-yl]methyl]-1-benzofuran-2-carboxamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H18N2O2S
assistant