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