You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named [2-[4-methyl-3-(methylsulfamoyl)anilino]-2-oxoethyl] (2S)-2-hydroxy-2-phenylacetate by IUPAC nomenclature, provide its molecular formula.
user
C18H20N2O6S
assistant