You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[(6aS)-9,10-dimethoxy-5,11-dioxo-6aH-isoindolo[2,1-a]quinazolin-6-yl]-N-(3H-benzimidazol-5-yl)acetamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C26H21N5O5
assistant