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 (1R,2S)-2-[[[2-cyclobutyl-2-(9H-fluoren-9-ylmethoxycarbonylamino)acetyl]amino]methyl]cyclopropane-1-carboxylic acid .
user
C26H28N2O5
assistant