You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
cyclopropyl-[4-[3-(4-methylphenyl)triazolo[4,5-d]pyrimidin-7-yl]piperazin-1-yl]methanone is the IUPAC name of a molecule. Please give its molecular formula.
user
C19H21N7O
assistant