You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named tert-butyl 2-(4-cyano-2-nitrophenyl)-4-(4-ethyl-3-iodophenyl)-4-methyl-3-oxopentanoate by IUPAC nomenclature, provide its molecular formula.
user
C25H27IN2O5
assistant