You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named 5-[23-tert-butyl-12,16-bis(2H-pyridin-1-yl)-15-(2H-pyrimidin-1-yl)-10,27-dioxaheptacyclo[15.11.0.02,14.03,11.04,9.020,28.021,26]octacosa-1(17),2,4(9),5,7,11,13,15,18,20(28),21(26),22,24-tridecaen-7-yl]-4aH-phenanthridine by IUPAC nomenclature, provide its molecular formula.
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C57H45N5O2
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