You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-ethyl-N'-[(1-hydroxy-2,3-dihydroinden-1-yl)methyl]-4-(1-methylpyrazol-4-yl)-3-oxopiperazine-1-carboximidamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H28N6O2
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