You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-ethyl-5-[(3-methyl-1,2,4-thiadiazol-5-yl)sulfanyl]-2-(propylamino)pentanoic acid The above is the IUPAC name of a molecule. Write its molecular formula.
user
C13H23N3O2S2
assistant