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

Difficulty: Very easy (0)

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

Difficulty: Easy (0)

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

Difficulty: Easy (0)

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

Difficulty: Very easy (0)