You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
ethyl (3R)-1-[(3R)-1-[4-[(3S)-3-[(3S)-3-ethoxycarbonylpiperidin-1-ium-1-yl]-2,5-dioxopyrrolidin-1-yl]phenyl]-2,5-dioxopyrrolidin-3-yl]piperidin-1-ium-3-carboxylate is the IUPAC name of a molecule. Please give its molecular formula.
user
C30H40N4O8+2
assistant