You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
5-[[[2-ethyl-2-(9H-fluoren-9-ylmethoxycarbonylamino)butanoyl]amino]methyl]oxolane-3-carboxylic acid The above is the IUPAC name of a molecule. Write its molecular formula.
user
C27H32N2O6
assistant