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

Difficulty: Very easy (0)

						1
				2	4		6
				1			7
	4				8
		8				6
7			1
3		2	6
	2

Difficulty: Very hard (0)

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

Difficulty: Very hard (0)

5	8				6		2
					2	1
	6					8
					4		6
2		5
	1					3
	4	2
3		1				2	8

Difficulty: Very easy (0)