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