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