You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(3aS,6aS)-5,5-dioxo-3-(2-phenylethyl)-3a,4,6,6a-tetrahydrothieno[3,4-d][1,3]thiazol-2-imine is the IUPAC name of a molecule. Please give its molecular formula.
user
C13H16N2O2S2
assistant