You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named (11S)-7,15,17,26-tetrahydroxyheptacyclo[19.7.1.02,11.02,20.03,8.014,19.025,29]nonacosa-1(29),3(8),4,6,14(19),15,17,20,22,25,27-undecaene-9,13,24-trione by IUPAC nomenclature, provide its molecular formula.
user
C29H18O7
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