You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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ethyl 2-[2-[(2R)-2-[2-(6-carbamimidoyl-1-ethylindol-2-yl)ethyl]pyrrolidin-2-yl]-2-oxoethyl]benzoate is the IUPAC name of a molecule. Please give its molecular formula.
user
C28H34N4O3
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