You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named N-(4-fluorophenyl)-2-[(4-methoxyphenyl)methylamino]-4-oxo-3-phenyl-7,8-dihydro-5H-pyrido[4,3-d]pyrimidine-6-carboxamide by IUPAC nomenclature, provide its molecular formula.
user
C28H26FN5O3
assistant