You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2S)-N-butyl-2-[(3,4-dichlorophenyl)methyl-[2-[(4-nitrophenyl)methylsulfanyl]acetyl]amino]butanamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C24H29Cl2N3O4S
assistant