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

Difficulty: Very easy (0)

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

Difficulty: Very easy (0)

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

Difficulty: Very easy (0)

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

Difficulty: Medium (0)