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

Difficulty: Very hard (0)

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

Difficulty: Very easy (0)

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

Difficulty: Very easy (0)

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

Difficulty: Very easy (0)