+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
      |              |     |     |     |     |
+  +  +--+--+--+--+  +--+  +  +  +  +  +  +  +
|  |              |     |  |  |     |     |  |
+--+--+--+--+--+  +--+  +  +--+--+--+--+  +  +
|              |     |  |        |     |  |  |
+  +--+--+--+  +  +  +  +--+--+  +  +  +  +  +
|  |        |  |  |     |     |  |  |     |  |
+  +  +--+  +  +  +--+--+--+  +  +  +  +--+  +
|  |  |     |     |           |  |  |     |  |
+  +  +  +--+--+--+  +--+--+  +  +--+--+  +  +
|     |     |        |     |  |     |     |  |
+--+--+--+  +  +--+--+--+  +  +  +  +--+  +--+
|        |     |           |     |     |     |
+  +--+--+  +--+  +--+--+--+--+--+--+  +  +  +
|           |     |     |              |  |  |
+--+--+  +--+  +--+--+  +  +--+--+--+--+--+  +
|        |     |     |     |           |     |
+  +--+--+  +--+--+  +  +--+  +--+--+  +  +--+
|  |        |     |  |     |  |        |  |  |
+  +  +--+--+  +  +  +--+  +  +  +--+--+  +  +
|  |  |        |     |  |     |        |     |
+  +  +  +--+--+--+--+  +--+--+--+  +  +--+  +
|     |                             |     |  |
+--+--+--+--+--+--+--+  +--+--+--+--+--+  +  +
|     |                 |              |     |
+  +  +  +--+--+--+  +--+--+--+--+--+  +--+  +
|  |  |     |     |           |     |     |  |
+  +--+--+  +  +  +--+--+--+  +  +  +--+  +  +
|           |  |                 |     |      
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+