CCCSc1nc(-c2ccc(OC)cc2)c(C#N)c(=O)n1C1OC(COC(C)=O)C(OC(C)=O)C(OC(C)=O)C1OC(C)=O
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.