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

Difficulty: Harder (0)

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

Difficulty: Easy (0)

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

Difficulty: Easy (0)

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

Difficulty: Very easy (0)