You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[2-(3-methylanilino)-2-oxoethyl] 4-[[4-chloro-3-(trifluoromethyl)phenyl]sulfonylamino]butanoate is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H20ClF3N2O5S
assistant