You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the molecule identified by N-(5-chloro-2-methoxyphenyl)-2-[[5-[1-(2,4-dichlorophenoxy)ethyl]-4-ethyl-1,2,4-triazol-3-yl]sulfanyl]acetamide ?
user
C21H21Cl3N4O3S
assistant