You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(1S)-N-[(3,5-dimethyl-1-propan-2-ylpyrazol-4-yl)methyl]-1-[1-(3-fluorophenyl)-5-methylpyrazol-4-yl]ethanamine is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H28FN5
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