+-- Ground level --------------------------------+
| |
| *--*--* |
| / | \ |
| / | \ |
| * * M * * |
| / /| / \ |\ \ |
| / / |/ \| \ \ |
| * * * * * * |
| / / \ \ |
| / / \ \ |
| * * * * *--* * |
| | | / \ |\ | | |
| | | / \ | \| | |
| * *--* * * * * |
| | / | | |
| | / | | |
| *> * * * * * |
| | / /| / | |
| | / / |/ | |
| * <*--* * * * * |
| / | \ /| \ |
| / | \ / | \ |
| * * *--* * * |
| / | / \ |
| / | / \ |
| * * *--* * * |
| / | | \ |
| / | | \ |
| * *--* *--*--* * |
| \ / | / |
| \ / | / |
| * *--* * * * |
| \ \ / \ | / |
| \ \ / \ | / |
| * * * * * * |
| \ |\ / / / |
| \ | \ / / / |
| * * *--*--*--* * |
| | / \ | |
| | / \ | |
| * * *--* * * |
| | |\ / | | |
| | | \ / | | |
| * * * * * * |
| | \ /| | |
| | \ / | | |
| * * * *--* * |
| |> \ / / |
| | \ < / / |
| * * * * |
| \ \ | / |
| \ \ | / |
| * * * * |
| \ | / |
| \ | / |
| * M * |
| \ / |
| \ / |
| * |
| | |
| | |
| * * * * |
| |\ | / \ |
| | \|/ \ ^ |
| * * * * |
| v \ / |
| \ / |
| *--* |
| |
+------------------------------------------------+