You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Under IUPAC nomenclature, a molecule named (3-chloro-4-methylthiophen-2-yl)-(3-oxa-9-azaspiro[5.5]undecan-9-yl)methanone is given. What is its corresponding molecular formula?
user
C15H20ClNO2S
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