You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance 2-[(2S)-2-(2-fluorophenyl)-3-[(4-fluorophenyl)-hydroxymethylidene]-4,5-dioxopyrrolidin-1-yl]ethyl-dimethylazanium .
user
C21H21F2N2O3+
assistant