2 2
3 3
3 1

....+---+---+
.../   /   /|
..+---+---+ |
./   /|   | +
+---+ |   |/|
|   | +---+ |
|   |/|   | +
+---+ |   |/|
|   | +---+ |
|   |/   /| +
+---+---+ |/.
|   |   | +..
|   |   |/...
+---+---+....