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