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Easy · Puzzle #520
3
9
2
5
4
6
2
8
6
5
1
3
2
9
1
5
7
8
7
5
8
6
9
3
1
3
7
5
8
6
2
4
1
3
9
8
4
7
5
8
2
6
3
9
6
7
1
2
5
When a box has only two empty cells, you know exactly which two digits fill them.
When a box has only two empty cells, you know exactly which two digits fill them.
X-Wing: if a digit appears in exactly two cells in two rows, and those cells share the same two columns, eliminate that digit from those columns elsewhere.
X-Wing: if a digit appears in exactly two cells in two rows, and those cells share the same two columns, eliminate that digit from those columns elsewhere.