You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named N-(2,3-dimethylphenyl)-2-[methyl-[[6-methyl-5-(4-methylphenyl)-4-oxo-3H-thieno[2,3-d]pyrimidin-2-yl]methyl]amino]acetamide by IUPAC nomenclature, provide its molecular formula.
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C26H28N4O2S
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