You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2S)-N-(2,6-difluorophenyl)-1-[(2S)-3,3-dimethyl-2-[[(2S)-2-(methylamino)propanoyl]amino]butanoyl]pyrrolidine-2-carboxamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H30F2N4O3
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