You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(3E,8R,12R)-12-(2-aminoacetyl)-8-(3-oxobutyl)-1,6-dithiacyclotridec-3-en-9-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C17H27NO3S2
assistant