You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named (2R)-N-[3-[methyl(methylsulfonyl)amino]phenyl]-2-(5,6,7,8-tetrahydronaphthalen-1-yloxy)propanamide by IUPAC nomenclature, provide its molecular formula.
user
C21H26N2O4S
assistant