O=C(COc1ccc(OCC(=O)N2C(=O)CC(=O)N(c3ccccc3)C2=S)cc1)N1C(=O)CC(=O)N(c2ccccc2)C1=S
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.