You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N'-[4-[5-[(4-propylphenyl)sulfonylamino]-1,2,4-thiadiazol-3-yl]phenyl]butanediamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H23N5O4S2
assistant