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

Difficulty: Super easy (0)

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

Difficulty: Easy (0)

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

Difficulty: Very easy (0)

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

Difficulty: Hard (0)