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-benzyl-2-[[6-[(4-chlorophenyl)methyl]-4-oxo-3,5,7,8-tetrahydropyrido[4,3-d]pyrimidin-2-yl]sulfanyl]acetamide by IUPAC nomenclature, provide its molecular formula.
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C23H23ClN4O2S
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