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