You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1,1'-biphenyl;2-chlorobenzene-1,3-diol;4-(2-pyridin-4-ylethyl)pyridine;2,3,5,6-tetramethylpyrazine is the IUPAC name of a molecule. Please give its molecular formula.
user
C44H44Cl2N4O4
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