O=C(Nc1cccc(-c2nn3ccccc3c2-c2ccnc(Nc3ccc4c(c3)CNCC4)n2)c1)c1c(F)cccc1F
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?