CC(=O)O.Nc1nc(N)c2nc(CNc3ccc(C(=O)NC(CCNC(=O)c4ccccc4C(=O)O)C(=O)O)cc3)cnc2n1
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.