You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(5S)-5-[[4-[4-[[(5S)-2,4-dioxo-1,3-thiazolidin-5-yl]methyl]phenoxy]phenyl]methyl]-1,3-thiazolidine-2,4-dione is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H16N2O5S2
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