You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-[[(1R,2S)-2-[(9H-fluoren-9-ylmethoxycarbonylamino)methyl]cyclohexanecarbonyl]amino]butanoic acid is the IUPAC name of a molecule. Please give its molecular formula.
user
C27H32N2O5
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