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