You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
8-methyl-7-(4-nitro-2-pyrrolidin-1-ylsulfonylphenyl)-3-propan-2-yl-6,8-dihydro-5H-[1,2,4]triazolo[4,3-a]pyrazine The above is the IUPAC name of a molecule. Write its molecular formula.
user
C19H26N6O4S
assistant