You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule 1,1-difluoro-2-oxo-2-(5,5,6,6-tetrafluorospiro[1,3-dioxepane-2,6'-tricyclo[3.3.1.03,7]nonane]-3'-yl)oxyethanesulfonic acid into molecular formula.
user
C15H16F6O7S
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