You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance 5-fluoro-2-N-[4-(4-methylpiperazin-1-yl)phenyl]-4-N-(oxolan-2-ylmethyl)pyrimidine-2,4-diamine .
user
C20H27FN6O
assistant