You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[(1R)-1-[5-(4-fluorophenyl)-1,3,4-oxadiazol-2-yl]ethyl] 5,6-dihydro-4H-cyclopenta[b]thiophene-2-carboxylate The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H15FN2O3S
assistant