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