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