You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named [2-(3-fluoroanilino)-2-oxoethyl]-methyl-[2-oxo-2-(4-pyrrolidin-1-ylanilino)ethyl]azanium by IUPAC nomenclature, provide its molecular formula.
user
C21H26FN4O2+
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