1	5	4	12						11
			2			9	4		5
11	8		3	6						10	9
						1		8		6
				11		8			10		5
12			6								1
1								9			8
7		9			10		12
	2		5		4
3	7						2	10		1	11
		1		4	9			5
	10						3	6	2	12

Difficulty: Very easy (0)

				11		7	5
7		11					3
8		5	4		10	6	1
	8		11	2				1	3		5
2							12	7	9		10
10									11	8
	7	8									1
6		10	3	9							4
11		4	12				6	5		2
				6	11	9		2	10		7
				10					1		9
				7	3		4

Difficulty: Hard (0)

				12	11		9				10
5	11					10			7		1
				6				2	8		11
	2			5	12	9			6
	6			10			4		5
	10	5	4		2
						6		8	1	11
		11		8			3			12
		1			4	11	10			7
6		12	1				8
11		10			9					3	5
2				11		7	5

Difficulty: Easy (0)

10						1			5		3
		5		4	12				6		10
6	11					5					8
		9		2			8
	8			7	4					10
7			5				3		9	4	6
9	4	10		8				3			5
	7					11	4			9
				1			9		12
2					11					5	4
11		6				12	2		8
12		1			9						2

Difficulty: Very easy (0)