CCc1c(O)c(O)c(C(C)=O)c2c(O)c(-c3c(C)cc4c(CC)c(O)c(O)c(C(C)=O)c4c3O)c(C)cc12
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.