You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[(3S)-1-(4-chlorophenyl)sulfonylpiperidin-3-yl]-5-[(4-fluorophenyl)methyl]-1,3,4-oxadiazole The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H19ClFN3O3S
assistant