20
12
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
|           |       |           |       |               |   |       |           |
+   +   +   +   +   +   +---+---+   +   +   +---+   +   +   +   +   +   +   +   +
|   |   |       |   |   |           |   |       |   |   |   |   |       |   |   |
+---+---+---+---+   +   +   +---+---+   +---+---+   +   +   +   +---+---+   +---+
|                   |       |       |       |       |   |       |       |       |
+   +   +---+---+---+---+   +   +---+---+   +   +   +   +---+---+   +---+---+   +
|   |       |               |                   |   |       |       |           |
+   +---+---+   +---+   +---+---+---+---+---+---+---+---+   +---+   +   +---+   +
|   |               |           |       |               |           |   |       |
+   +   +---+---+---+---+---+   +---+   +   +---+---+   +   +---+   +   +---+   +
|   |       |       |           |       |           |       |       |       |   |
+   +---+   +---+   +   +---+---+   +---+---+---+   +---+---+---+---+---+   +   +
|       |   |       |       |                   |                           |   |
+---+   +   +---+   +---+   +   +---+   +---+---+---+---+---+---+---+---+---+   +
|       |       |   |   |   |   |                           |               |   |
+   +---+---+   +   +   +   +---+   +---+---+---+---+---+   +   +---+   +---+   +
|           |       |   |       |           |   |       |   |       |           |
+---+---+   +---+---+   +---+   +   +---+   +   +---+   +   +---+---+---+   +---+
|           |           |               |   |   |   |   |               |       |
+   +---+---+---+   +   +   +---+---+---+   +   +   +   +---+---+---+   +---+   +
|       |       |   |   |           |       |   |       |           |   |       |
+---+   +   +   +   +---+   +   +   +---+---+   +   +---+   +   +---+   +   +---+
|           |               |   |               |           |           |       |
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
