CCCCCCCCCCCC(=O)Oc1c(Cl)cc(Cl)c(OC(=O)C(=O)Oc2c(Cl)cc(Cl)c(OC(=O)CCCCCCCCCCC)c2Cl)c1Cl
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.