return [[ 0, 0, 0, 0 ],
[ 0, 0, 0, 4 ],
[ 0, 0, 0, 8 ],
[ 5, 0, 0, 0 ],
[ 5, 0, 0, 4 ],
[ 5, 0, 0, 8 ],
[ 10, 0, 0, 0 ],
[ 10, 0, 0, 4 ],
[ 10, 0, 0, 8 ],
[ 15, 0, 0, 0 ],
[ 15, 0, 0, 4 ],
[ 15, 0, 0, 8 ]];;