# This puzzle was obtained from sudoku.com
.6.|1.4|.5.
..8|3.5|6..
2..|...|..1
---+---+---
8..|4.7|..6
..6|...|3..
7..|9.1|..4
---+---+---
5..|...|..2
..7|2.6|9..
.4.|5.8|.7.
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# http://www.sudoku.org.uk/bifurcation.htm
1 0 0 9 0 7 0 0 3
0 8 0 0 0 0 0 7 0
0 0 9 0 0 0 6 0 0
0 0 7 2 0 9 4 0 0
4 1 0 0 0 0 0 9 5
0 0 8 5 0 4 3 0 0
0 0 3 0 0 0 7 0 0
0 5 0 0 0 0 0 4 0
2 0 0 8 0 6 0 0 9

# This puzzle has multiple solutions
1 2 3 4 5 6 7 8 9
0 6 0 0 0 0 0 3 0
0 7 0 0 0 0 0 4 0
7 8 9 1 2 3 4 5 6
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0
4 5 6 7 8 9 1 2 3
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0