You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 6-cyclopropyl-N-[4-(5-cyclopropyl-4-piperazin-1-ylpyrido[3,4-d]pyrimidin-2-yl)pyridin-2-yl]-2,4-difluoropyridin-3-amine by IUPAC nomenclature, provide its molecular formula.
user
C27H26F2N8
assistant