You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named 5-[[2-[4-(2-hydroxyethyl)piperazin-1-yl]-7-methyl-4-oxopyrido[1,2-a]pyrimidin-3-yl]methylidene]-3-propan-2-yl-2-sulfanylidene-1,3-thiazolidin-4-one by IUPAC nomenclature, provide its molecular formula.
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C22H27N5O3S2
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