You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-[N-[[2-[[5-(4-chlorophenyl)-4-ethyl-1H-1,2,4-triazol-4-ium-3-yl]sulfanyl]acetyl]amino]-C-ethylcarbonimidoyl]phenolate is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H22ClN5O2S
assistant