COC(=O)CN1C(=O)[C@H]2[C@@H](C)C3=C4[C@@H](CC(C(=O)OC)=C[C@@H](C(=O)OC)[C@H]4[C@@](C)(NC(=O)c4ccccc4)C3=O)[C@H]2C1=O
Molecules with a polar surface area of greater than 140 angstroms squared (Å2) tend to be poor at permeating cell membranes. What's the psa of this molecule?