You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 1-[4-[(5-chlorothiophen-2-yl)methyl]piperazin-1-yl]-2-(6-methylpyridin-3-yl)ethanone into its molecular formula.
user
C17H20ClN3OS
assistant