Nc1ncnc2c1ncn2C1OC(COC2C(CO)OC(OC(C(=O)O)C(O)C(OP(=O)(O)O)C(O)C(=O)O)C(O)C2O)C(O)C1O
Molecules with a polar surface area of greater than 60 angstroms squared (Å2) is hard to pass brain blood barrier. What's the psa of this molecule?