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

Difficulty: Very easy (0)

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

Difficulty: Super easy (0)

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

Difficulty: Medium (0)

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

Difficulty: Easy (0)