You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(3aS,5R,7aR)-5-(4-benzyl-3,5-dioxo-1,2,4-triazolidin-1-yl)-2-(4-chlorophenyl)-3a,4,5,7a-tetrahydroisoindole-1,3-dione is the IUPAC name of a molecule. Please give its molecular formula.
user
C23H19ClN4O4
assistant