You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule (2S)-2-amino-N-[2-[4-[(3-fluorophenyl)methoxy]-2-methylanilino]-2-oxoethyl]-3-methylbutanamide;hydrochloride into molecular formula.
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C21H27ClFN3O3
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