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

Difficulty: Very easy (0)

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

Difficulty: Very hard (0)

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

Difficulty: Very easy (0)

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

Difficulty: Very easy (0)