You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule 2-ethyl-N-[[2-(2-methylimidazol-1-yl)phenyl]methyl]-6-oxo-1H-pyridine-3-carboxamide;formic acid into molecular formula.
user
C20H22N4O4
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