O=[N+]([O-])c1ccc(S[C@H]2[C@H]3C[C@@H](Cl)[C@@H]2c2c(-c4ccccc4)[nH]c(-c4ccccc4)c23)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.