[ [ 1,-1,1,0, 0,0, 0,0,0, 0, 1 ],
  [ 0, 0,0,1,-1,0, 0,0,0, 0, 0 ],
  [ 0, 0,0,0, 0,1,-1,1,0, 0,-1 ],
  [ 0, 0,0,0, 0,0, 0,0,1,-1, 0 ] ]