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