You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 5-ethyl-1-(6-methoxypyridazin-3-yl)-N-(2-pyrrolidin-1-yl-2-thiophen-2-ylethyl)pyrazole-4-carboxamide into its molecular formula.
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C21H26N6O2S
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