You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named (6R,7R)-7-[[(2Z)-2-(2-amino-1,3-thiazol-4-yl)-2-methoxyiminoacetyl]amino]-3-[(4-ethyl-1,2,4-triazol-3-yl)sulfanylmethyl]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid by IUPAC nomenclature, provide its molecular formula.
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C18H20N8O5S3
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