You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-methyl-N-[3-[1-[(5-methyl-1,3,4-thiadiazol-2-yl)amino]-1-oxobutan-2-yl]sulfanylphenyl]benzamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H22N4O2S2
assistant