-------------------------------------
|     7   1 |         4 |           |
|   +   +   +   +   +   +   +   +   |
|           | 1         | 9   3     |
|   +   +   +   +   +   +   +   +   |
| 8         |     2   9 |           |
|---+---+---+---+---+---+---+---+---|
|         5 | 8         |     6   7 |
|   +   +   +   +   +   +   +   +   |
| 6       4 |           |         5 |
|   +   +   +   +   +   +   +   +   |
|         8 |           |           |
|---+---+---+---+---+---+---+---+---|
| 5   1     | 4         | 2         |
|   +   +   +   +   +   +   +   +   |
|           |         2 | 5   1     |
|   +   +   +   +   +   +   +   +   |
|           |           | 6         |
-------------------------------------

          DIFFICULTY: 1.25