You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-amino-4-[(2S)-2-[5-chloro-3-(3-fluorophenyl)-1H-1,2,4-triazin-2-yl]pyrrolidin-1-yl]-6H-pyrimido[4,5-d]pyrimidin-5-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C19H17ClFN9O
assistant