You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Convert the IUPAC name of a molecule ethyl (4S)-2-oxo-6-[[1-[[(2R)-oxolan-2-yl]methyl]tetrazol-5-yl]sulfanylmethyl]-4-thiophen-2-yl-3,4-dihydro-1H-pyrimidine-5-carboxylate into molecular formula.
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C18H22N6O4S2
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