+-----+-----+-----+-----+-----+-----+-----+-----+-----+
|     |     |     "     |     |     "     |     |     |
|  8  |  4 <<< 5 <<< 7 <<< 9  |  1  "  2  |  6 >>> 3  |
|     |     |     "     |     |  ^  "     |  ^  |     |
+-----+-----+-----+-----+-----+--^--+-----+--^--+-----+
|     |     |     "     |     |  ^  "     |  ^  |     |
|  1  |  9  |  6 >>> 5 >>> 3  |  2 <<< 4  |  7  |  8  |
|  ^  |     |     "     |     |     "  ^  |     |  v  |
+--^--+-----+-----+-----+-----+-----+--^--+-----+--v--+
|  ^  |     |     "     |     |     "  ^  |     |  v  |
|  2  |  7  |  3 <<< 8  |  6  |  4  "  9  |  1  |  5  |
|  ^  |     |  v  "     |  ^  |     "     |  ^  |  v  |
+==^==+=====+==v==+=====+==^==+=====+=====+==^==+==v==+
|  ^  |     |  v  "     |  ^  |     "     |  ^  |  v  |
|  6  |  1 <<< 2  "  9 >>> 7  |  5  "  3  |  8  |  4  |
|     |     |     "     |     |     "     |  ^  |     |
+-----+-----+-----+-----+-----+-----+-----+--^--+-----+
|     |     |     "     |     |     "     |  ^  |     |
|  7  |  5  |  8 >>> 6  |  4  |  3 >>> 1  |  9  |  2  |
|     |  v  |     "     |     |     "     |     |     |
+-----+--v--+-----+-----+-----+-----+-----+-----+-----+
|     |  v  |     "     |     |     "     |     |     |
|  4  |  3  |  9  "  1  |  2 <<< 8  "  6 >>> 5  |  7  |
|  ^  |  v  |     "     |  v  |     "  ^  |     |  v  |
+==^==+==v==+=====+=====+==v==+=====+==^==+=====+==v==+
|  ^  |  v  |     "     |  v  |     "  ^  |     |  v  |
|  5  |  2  |  7  "  4  |  1  |  9 >>> 8  |  3  |  6  |
|  ^  |     |  v  "     |     |     "     |     |  v  |
+--^--+-----+--v--+-----+-----+-----+-----+-----+--v--+
|  ^  |     |  v  "     |     |     "     |     |  v  |
|  9  |  8  |  4 >>> 3  |  5 <<< 6 <<< 7  |  2  |  1  |
|     |  v  |     "  v  |     |     "     |     |     |
+-----+--v--+-----+--v--+-----+-----+-----+-----+-----+
|     |  v  |     "  v  |     |     "     |     |     |
|  3 <<< 6  |  1  "  2  |  8 >>> 7 >>> 5 >>> 4  |  9  |
|     |     |     "     |     |     "     |     |     |
+-----+-----+-----+-----+-----+-----+-----+-----+-----+