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