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