COC(=O)[C@H](CO)n1cc(-c2cc(C(=O)N3CCN(C(=O)OC(C)(C)C)CC3)cc(-c3cn([C@@H](CC(C)C)C(=O)OC(C)(C)C)nn3)c2)nn1
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.