COc1ccc(C2c3[nH]c4ccccc4c3C[C@H]3C(=O)N(c4ccccc4C(=O)N4CCC(C(=O)O)CC4)C(=O)N23)cc1
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.