You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-[(2'S,3S,4'S)-4'-hydroxy-4-oxospiro[2H-chromene-3,3'-thiolane]-2'-yl]benzonitrile is the IUPAC name of a molecule. Please give its molecular formula.
user
C19H15NO3S
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