[ [ -1, 0, 0, 0, 1, 0, 0, 0 ],
  [  2,-1, 1, 0, 0, 0, 0, 0 ],
  [  0, 1,-1,-5, 0,-1, 1, 0 ],
  [  0, 0, 0, 3,-1, 0, 0, 0 ],
  [  0, 1,-1, 2, 0, 1,-1,-1 ],
  [  0,-1, 1, 0,-1, 0, 0, 1 ],
  [  0, 1,-1, 0, 1, 0, 0,-1 ],
  [  0, 0, 0, 0, 0, 0, 0, 0 ],
  [ -1, 0, 0, 0, 0, 0, 0, 0 ],
  [  0, 0, 0, 0, 0, 1,-1, 0 ],
  [  0, 0, 0, 0, 0,-1, 1, 0 ] ]