You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(1R,3S,4S)-2-(4-fluorophenyl)sulfonyl-3-[(3-methoxyphenoxy)methyl]-2-azabicyclo[2.2.1]heptane The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H22FNO4S
assistant