You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named 2-[(2-pyridin-4-ylpiperazin-1-yl)methyl]-3H-thieno[3,2-d]pyrimidin-4-one;2,2,2-trifluoroacetic acid by IUPAC nomenclature, provide its molecular formula.
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C18H18F3N5O3S
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