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

Difficulty: Very easy (0)

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

Difficulty: Very easy (0)

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

Difficulty: Very hard (0)

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

Difficulty: Very hard (0)