CNc1ccc2oc(C[C@H]3O[C@@]4(CC[C@H]3C)O[C@H]([C@H](C)C(=O)c3ccc[nH]3)[C@H](C)C[C@H]4C)nc2c1C(=O)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.