CC(=O)OC1CC2C(C)(C)C(=O)C3OC3[C@]2(C)C2CC[C@@]3(C)C(c4ccoc4)OC(=O)C4OC43[C@]12C
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.