You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
methyl (2S,5S)-2-ethyl-7-methyl-3-oxo-5-thiophen-2-yl-5H-[1,3]thiazolo[3,2-a]pyrimidine-6-carboxylate The above is the IUPAC name of a molecule. Write its molecular formula.
user
C15H16N2O3S2
assistant