You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[(2-chlorophenyl)methyl]-N-[(2S)-1-(methylamino)-1-oxopropan-2-yl]-4-(2-oxobenzo[cd]indol-1-yl)butanamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C26H26ClN3O3
assistant