You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(4'aR,5R)-1,3'-diphenylspiro[1,3-diazinane-5,5'-2,4,4a,6-tetrahydro-1H-pyrazino[1,2-a]quinoline]-2,4,6-trione The above is the IUPAC name of a molecule. Write its molecular formula.
user
C27H24N4O3
assistant