You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named [2-[(2S)-1-[(2S)-2-[[(2S)-2-[(2-methylpropan-2-yl)oxycarbonylamino]propanoyl]amino]propanoyl]pyrrolidin-2-yl]-2-oxoethyl]-propan-2-ylcarbamic acid by IUPAC nomenclature, provide its molecular formula.
user
C21H36N4O7
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