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-(tert-butylcarbamoylamino)-2-oxoethyl] (3S,7aR)-5-oxo-7a-phenyl-2,3,6,7-tetrahydropyrrolo[2,1-b][1,3]thiazole-3-carboxylate into molecular formula.
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C20H25N3O5S
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