You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2S)-1-[(2S)-2-(9H-fluoren-9-ylmethoxycarbonylamino)-3,3-dimethylbutanoyl]-4,4-difluoropyrrolidine-2-carboxylic acid is the IUPAC name of a molecule. Please give its molecular formula.
user
C26H28F2N2O5
assistant