You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[(2R)-1-(ethylamino)-1-oxopropan-2-yl]-N-[(4-fluorophenyl)methyl]-4-(2-oxobenzo[cd]indol-1-yl)butanamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C27H28FN3O3
assistant