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

Difficulty: Very easy (0)

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

Difficulty: Easy (0)

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

Difficulty: Harder (0)

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

Difficulty: Easy (0)