C/C1=N/NC(=S)NCCCN2CCN(CCCNC(=S)N/N=C(/C)C=NNC(=S)NCCCN3CCN(CCCNC(=S)NN=C1)CC3)CC2
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.