You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-(2-chloro-4,6-dimethylphenyl)-2-(6,7,8,9-tetrahydro-5H-[1,2,4]triazolo[4,3-a]azepin-3-ylsulfanyl)acetamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C17H21ClN4OS
assistant