You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-(4-benzoylpiperazine-1-carbonyl)-4-[(4-methoxyphenyl)methyl]pyrido[2,3-b]pyrazin-3-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C27H25N5O4
assistant