You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[2-(2-fluorophenyl)ethyl]-1-[2-[4-(3-oxobutyl)phenoxy]acetyl]piperidine-4-carboxamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C26H31FN2O4
assistant