You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-[[1-[3-(4-fluorophenyl)sulfonylpropyl]pyrrolidin-2-yl]methyl]-2,6-dimethylmorpholine is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H31FN2O3S
assistant