12
8
+---+---+---+---+---+---+---+---+---+---+---+---+
|                   |           |       |   |   |
+   +---+---+   +---+---+---+   +   +---+   +   +
|           |           |                   |   |
+---+   +   +---+   +---+   +---+---+---+---+   +
|   |   |   |       |       |           |       |
+   +---+---+   +---+   +---+   +---+---+---+   +
|           |                           |       |
+   +   +   +   +---+   +---+---+---+   +---+   +
|   |   |           |   |   |       |   |       |
+---+   +---+   +   +---+   +   +---+   +   +---+
|   |   |   |   |   |       |   |   |   |       |
+   +   +   +---+   +---+   +   +   +---+---+   +
|       |   |               |       |   |   |   |
+---+   +   +   +---+   +---+   +---+   +   +   +
|       |       |                               |
+---+---+---+---+---+---+---+---+---+---+---+---+
