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

Difficulty: Very easy (0)

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

Difficulty: Hard (0)

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

Difficulty: Easy (0)

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

Difficulty: Very easy (0)