You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(7R)-7-(2-hydroxyphenyl)-2-(4-pyridin-2-ylpiperazin-1-yl)-7,8-dihydro-6H-quinazolin-5-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C23H23N5O2
assistant