You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2S)-7-[2-[1-[(5-fluoro-2-methylphenyl)methyl]triazol-4-yl]ethyl]-1,2,5-trimethyl-2,4-dihydropyrido[3,4-b]pyrazin-3-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C22H25FN6O
assistant