Minimum Sudoku

This page is concerned with the question of what is the smallest number of entries in a Sudoku puzzle that has a unique completion.

At the moment, there are examples of 17-hint uniquely completable Sudoku puzzles, but no known 16-hint examples. Hence I am collecting as many 17-hint examples as possible, in the hope that their analysis will yield some insight.

Currently I have a collection of 49151 distinct Sudoku configurations with 17 entries

Download the file containing all of them! (or the same file, but with the puzzles in minlex order).

This collection was mainly produced by my own software, although a few hundred have been sent to me by other people, in particular Glenn Fowler, Kohei Noshita and Håvard Graff. This collection is subject to Australian copyright law, but it may be freely used provided appropriate attribution is made to Gordon Royle and The University of Western Australia.

This work is licensed under a Creative Commons Attribution 2.5 License.

Now that new 17-clue Sudoku puzzles are becoming rarer to find, it would be sensible to try to retain puzzle-by-puzzle information about the initial discoverer.

Barring mistakes, these are guaranteed to be mathematically inequivalent in that no two of them can be translated to each other by any combination of the following operations

1. Permutations of the 9 symbols,
2. Transposing the matrix (that is, exchanging rows and columns),
3. Permuting (ie. rearranging) rows within a single block,
4. Permuting (ie. rearranging) columns within a single block,
5. Permuting the blocks row-wise,
6. Permuting the blocks column-wise.

This collection of operations forms a group of order

9! x 6^8 x 2

Note: although not immediately apparent, rotations and reflections are already included in the above list because they can be expressed as combinations of these operations.

This list also contains all the ones that I have found on the Web to date. More precisely, it contains ones that are mathematically equivalent to the ones that I have found on the Web. They have been transmogrified into the particular form here simply for my personal computational reasons. I will give the sources for these in more detail shortly, but in summary they come from a Japanese blog, some postings on the forums at www.sudoku.com and my own computations.

If you have any more 17-hint examples, then please email them to me at

gordon(AT)maths(DOT)uwa(DOT)edu(DOT)au

in plain text only. (All mail in HTML is automatically deleted due to my spam problems). I will automate this process (inlcuding detection of equivalence) shortly.

If you want to play with these (ie actually solve them), then I have a very simple-minded helper application in early development. Just click "transfer to helper" to activate it.

From To

Number 1 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 2 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 3 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 4 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 5 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 6 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 7 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 8 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 9 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 10 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 11 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 12 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 13 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 14 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 15 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 16 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 17 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 18 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 19 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 20 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 21 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 22 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 23 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 24 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 25 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 26 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 27 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 28 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 29 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 30 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 31 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 32 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 33 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 34 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 35 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 36 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 37 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 38 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 39 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 40 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 41 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 42 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 43 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 44 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 45 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 46 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 47 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 48 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 49 (transfer to helper)
(Transfer to Sudoku Solver)

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

Number 50 (transfer to helper)
(Transfer to Sudoku Solver)

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