You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule N-(1-ethylpyrazol-4-yl)-5-(4-methyl-6-oxo-1H-pyridin-3-yl)thiophene-2-carboxamide into molecular formula.
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C16H16N4O2S
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