You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Convert the IUPAC name of a molecule 1-[4-[2-(1-tert-butyl-2,5-dimethylpyrrol-3-yl)-2-oxoethyl]piperazin-1-yl]-2,2-dimethylpropan-1-one into molecular formula.
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C21H35N3O2
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