NCC1O[C@@H](OC2C(N)C[C@H](N)[C@@H](O[C@H]3OC(CO)C(O)C(N)C3O)C2O)C(N)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?