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