You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-(4,7-dimethyl-1,3-benzothiazol-2-yl)-3-(3-phenyl-1,2,4-oxadiazol-5-yl)propanamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H18N4O2S
assistant