You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the molecule identified by [N'-[[2-fluoro-3-[4-(6-methylpyridin-3-yl)piperazin-1-yl]phenyl]methyl]carbamimidoyl]carbamic acid ?
user
C19H23FN6O2
assistant