You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[3-[4-(2-methoxyphenyl)phenyl]piperazin-1-yl]-3-methyl-6-pyridin-4-ylpyrimidin-4-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C27H27N5O2
assistant