You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-[3-(2-ethyl-1,3-thiazol-4-yl)phenyl]-5-(3-methoxyphenyl)-1,2,4-oxadiazole The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H17N3O2S
assistant