You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-[4-[(2,6-dichlorobenzoyl)amino]phenyl]-2-(1,3-thiazolidine-4-carbonylamino)propanoic acid The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H19Cl2N3O4S
assistant