You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[4-(3,4-dimethylphenyl)-1,3-thiazol-2-yl]-5-phenyl-1,2-oxazole-3-carboxamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H17N3O2S
assistant