You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule 4-[(2S,3E)-2-(2-fluorophenyl)-3-[hydroxy-(4-nitrophenyl)methylidene]-4,5-dioxopyrrolidin-1-yl]butanoic acid .
user
C21H17FN2O7
assistant