return [[ 0, 0, 0, 0 ],
[ 0, 3, 0, 3 ],
[ 0, 6, 0, 6 ],
[ 0, 9, 0, 9 ],
[ 4, 0, 0, 0 ],
[ 4, 3, 0, 3 ],
[ 4, 6, 0, 6 ],
[ 4, 9, 0, 9 ],
[ 8, 0, 0, 0 ],
[ 8, 3, 0, 3 ],
[ 8, 6, 0, 6 ],
[ 8, 9, 0, 9 ]];;