You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-methyl-N-[(1S)-2,2,2-trichloro-1-(naphthalen-1-ylcarbamothioylamino)ethyl]benzamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H18Cl3N3OS
assistant