1
			8
4					8	7
	7			9				1
5								8
		4					1
9						6	5

Difficulty: Very easy (0)

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

Difficulty: Very easy (0)

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

Difficulty: Easy (0)

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

Difficulty: Very easy (0)