COC(=O)[C@H](C)[C@H]1CC[C@@](C)(C2CC3C(C)(C)[C@H]4CCC(C)=C[C@H]4C[C@@]3(C)O2)OO1
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.