return [[ 0, 0, 0, 0 ],
[ 0, 3, 0, 0 ],
[ 0, 6, 0, 0 ],
[ 0, 9, 0, 0 ],
[ 0, 12, 0, 0 ],
[ 0, 15, 0, 0 ],
[ 0, 18, 0, 0 ],
[ 0, 21, 0, 0 ],
[ 8, 0, 0, 0 ],
[ 8, 3, 0, 0 ],
[ 8, 6, 0, 0 ],
[ 8, 9, 0, 0 ],
[ 8, 12, 0, 0 ],
[ 8, 15, 0, 0 ],
[ 8, 18, 0, 0 ],
[ 8, 21, 0, 0 ],
[ 16, 0, 0, 0 ],
[ 16, 3, 0, 0 ],
[ 16, 6, 0, 0 ],
[ 16, 9, 0, 0 ],
[ 16, 12, 0, 0 ],
[ 16, 15, 0, 0 ],
[ 16, 18, 0, 0 ],
[ 16, 21, 0, 0 ]];;