7	8					1
				9		6	7
							2
4				1
1								3
				7				1
	3
	1	2		5
		7					8	2

Difficulty: Super easy (0)

5		3					6
					3	8
	6
					6	4
6								9
		2	9
							7
		6	5
	4					3		5

Difficulty: Very easy (0)

							7
6					7
			2
			9
		9	5		2	8
					8
					9
			8					6
	1

Difficulty: Very hard (0)

				5			9
8						5	6
			3
			5			9
		6		4
								1
	5	1			3
	8

Difficulty: Very easy (0)