COc1ccc2c(c1)[C@H]1[C@H](CO2)[C@H](c2ccccc2)[C@]2(C)C(=O)N(Cc3ccc(C)cc3)CC(=O)N12
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.