You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule (3S,6S,9S,15R)-15-benzyl-13-benzylsulfonyl-3-methyl-6-(2-methylsulfanylethyl)-9-propan-2-yl-1,4,7,10,13-pentazacyclopentadecane-2,5,8,11-tetrone into molecular formula.
user
C31H43N5O6S2
assistant