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

Difficulty: Very easy (0)

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

Difficulty: Very easy (0)

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

Difficulty: Very hard (0)

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

Difficulty: Very hard (0)