You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
5-[3-(3-ethyl-1,4-dithian-2-yl)-1,2,4-oxadiazol-5-yl]pentanoic acid The above is the IUPAC name of a molecule. Write its molecular formula.
user
C13H20N2O3S2
assistant