You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2S)-N-[(2R)-butan-2-yl]-2-[(2,6-dichlorophenyl)methyl-[2-[(4-fluorophenyl)methylsulfanyl]acetyl]amino]propanamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C23H27Cl2FN2O2S
assistant