CC(C)CCCC1(C)C=Cc2c(O)c3c(c(CCC(C)C)c2O1)OC12C(CC4CC1C(C)(C)OC2(CCC(C)C(=O)O)C4O)C3=O
PSA is a commonly used medicinal chemistry metric for the optimization of a drug's ability to permeate cells. Please predict psa of this molecule.