You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Under IUPAC nomenclature, a molecule named 1-[4-(4-methoxyphenoxy)-2-(4-methylpiperazin-1-yl)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-2-phenylethanone is given. What is its corresponding molecular formula?
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C27H31N5O3
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