You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[4-(4-nitrophenyl)piperazin-1-yl]-2-[1-(2-oxo-2-piperidin-1-ylethyl)indol-3-yl]ethane-1,2-dione The above is the IUPAC name of a molecule. Write its molecular formula.
user
C27H29N5O5
assistant