You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Under IUPAC nomenclature, a molecule named 5-[ethyl(thiophen-2-ylmethyl)amino]-4-(9H-fluoren-9-ylmethoxycarbonylamino)-5-oxopentanoic acid is given. What is its corresponding molecular formula?
user
C27H28N2O5S
assistant