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

Difficulty: Hard

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

Difficulty: Easy

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

Difficulty: Hard

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

Difficulty: Medium