O=C1c2ccccc2/C(=N\c2ccc3ccccc3c2)C1(C1=C(c2ccccc2)/C(=N/c2ccc3ccccc3c2)c2ccccc21)c1ccccc1
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.