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

Difficulty: Very easy (0)

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

Difficulty: Hard (0)

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

Difficulty: Very easy (0)

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

Difficulty: Very easy (0)