You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 5-[4-(furan-3-ylsulfonyl)piperazin-1-yl]-3-(5-phenyl-1,3,4-oxadiazol-2-yl)pyrazin-2-amine into its molecular formula.
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C20H19N7O4S
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