You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[4-[2-(2-cyclopentyl-4,6-dioxooxan-2-yl)ethyl]-2-fluorophenyl]-N-methylmethanesulfonamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H26FNO5S
assistant