You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule 6-chloro-3-[[3,4-dioxo-2-[[(1R)-1-phenylethyl]amino]cyclobuten-1-yl]amino]-2-hydroxy-N-methoxy-N-methylbenzenesulfonamide into molecular formula.
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C20H20ClN3O6S
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