You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2R)-2-amino-3-methyl-3-methylsulfanyl-1-[4-([1,2,4]triazolo[4,3-a]pyrimidin-5-yl)piperazin-1-yl]butan-1-one;dihydrochloride The above is the IUPAC name of a molecule. Write its molecular formula.
user
C15H25Cl2N7OS
assistant