You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 5-butyl-1-[6-(5-butyl-2-phenylindol-1-yl)-2-propylpyrimidin-4-yl]-2-phenylindole by IUPAC nomenclature, provide its molecular formula.
user
C43H44N4
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