[ [ -1, 0, 0,   0, 0, 0, 1,   0, 0, 1 ],
  [  1,-1, 0,   0, 0, 0, 0,   0, 1, 0 ],
  [  0, 1,-1,   0, 0, 0, 0,   0, 0, 0 ],
  [  0, 0, 1,  -1, 0, 0, 0,   0, 0, 0 ],
  [  0, 0, 0,   1,-1, 0, 0,   0, 0, 0 ],
  [  0, 0, 0,   0, 1,-1, 0,   0, 0, 0 ],
  [  0, 0, 0,   0, 0, 1,-1,  -1, 0, 0 ],
  [  0, 0, 0,   0, 0, 0, 0,   1,-1,-1 ],
  [ -1, 0, 0,-1/2, 0, 0, 0,-1/2, 0, 0 ],
  [  0,-1, 0,   0,-1, 0, 0,   0, 0,-1 ],
  [  0, 0, 0,   0, 0, 1, 0,   0, 0, 0 ],
  [  0, 0, 0,   0, 0, 0, 0,   0, 0, 1 ],
  [  0, 0, 0,   0, 0, 0, 1,   0, 1, 0 ],
  [  1, 0, 0, 1/2, 0, 0, 0, 1/2, 0, 0 ],
  [  0, 0, 0,   0, 0, 0, 0,   0, 0, 0 ] ]