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

Difficulty: Very easy (0)

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

Difficulty: Hard (0)

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

Difficulty: Easy (0)

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

Difficulty: Very easy (0)