You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 3-[3-acetyl-2-(3-ethoxy-4-hydroxyphenyl)-4-hydroxy-5-oxo-2H-pyrrol-1-yl]propyl-diethylazanium into its molecular formula.
user
C21H31N2O5+
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