2 9 1 5 5 4 9 7 3 5 6 8 1 7 1 6 4 9 1 5 3 2 1 2 5 4 8 3 4 1 21-05-2018.......hard 21-05-2018 www.daily-sudoku-puzzle.com

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

1=>(2,1) | 6=>(4,1) | 9=>(3,3) | 1=>(3,6) | 9=>(4,4) | 1=>(7,4) | 5=>(9,7) | 8=>(5,1) | 5=>(4,3) | 7=>(6,3) | 7=>(3,5) | 3=>(4,2) | 6=>(1,5) | 3=>(8,7) | 9=>(8,9) | 6=>(9,8) | 7=>(1,2) | 7=>(8,1) | 9=>(9,1) | 6=>(2,3) | 4=>(3,2) | 2=>(5,2) | 6=>(7,2) | 9=>(5,8) | 3=>(5,5) | 9=>(7,5) | 7=>(7,7) | 8=>(7,8) | 8=>(1,3) | 4=>(1,9) | 8=>(3,7) | 2=>(3,8) | 4=>(7,3) | 7=>(5,4) | 2=>(9,5) | 3=>(6,8) | 4=>(4,7) | 7=>(9,6) | 3=>(1,4) | 3=>(2,9) | 2=>(4,6) | 4=>(5,6) | 5=>(5,9) | 2=>(6,7) | 8=>(6,9) | 2=>(2,4) | 8=>(2,6) | 6=>(6,4) | 5=>(6,6) | 8=>(8,4) | 6=>(8,6) |