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