5x5x5x5 sudoku

From AJS.COM

Sudoku is a number puzzle game, which is very popular in Japan. This variant starts with a grid of 5x5 squares lined up in a 5x5 grid (so there are 25 cells across and down). To solve it, fill in empty cells with a number between 1 and 25 so that none of the 5x5 sub-squares have duplicate numbers and none of the rows or columns have duplicate numbers.

 __ __  3 __ __  12  8 __ 21 __  17  7 __ 20  9  __ __ 10 23 19  __ __ __ __ __
 19 __ __ __ __  15 17  9  4  3  10 __ __ __ 14   8  7  5 __ 21  __ 25 22 12 __
 23 __ 24 __ __  __ 20 __ 14 __  18 21 __  1 25   9  3  4  6 15  __ __ __ __  8
  4 __ __ __  9  13 __  1 __ 23  19  8 __ __  5  24 12 __ 18 11  17  3 14  7 21
 20 21 __  5 __  __ __ 10 18 24  __  3 __ __ __  25 22 16  1 17  __ __  2  4  9
 
 16 __ __ 12 __  25 19 11  2  7   1 15 17  4 13  __ __ 24  8 10  __ __ 20 23 __
 __ __ __ __  7   8 10 24 15 __  20 __ __  9 22  __ __ 25 16 __  __ __ __  6  4
 25  3 __  1 19  __ __ __ __  5  __  6 14 21 __  12 15 17 __ __  __  2 10 13 __
 __ __ __ __ 23  __  3 __ 13 21   2 12 __  5 16   4 14 __ 20  1  24  9 25 __ __
 15 __ 18 __  4  16 14 12 20 __  25 __ 19 10 23   6 21 13 __  3   5  8  1 __  7
 
 18 __ __ 15 __  __ __ __ 12 19   7 10 21 __ 17  __ __ __ __ __  22  1 __ __ __
 13 __ __ 22 25  10 24  2 17  6  __ 16 __ 23 20  21 __ __ __ __  __ __ 15  9 19
 17 __  8 __ __  __ 23 __  7 11  __ 22 __ 25 __   1 __ __ 19 14   2 __ __ __ __
 __ __ 11 19 21  __ __ __  5 __   3  4  9 __ __  23 20 __ 24 22  __ 17 18 10 __
  9  6 __  4 __  __ 16 21 22 __  15 __  1 __ 19  __ 10 __ __  8  25 11 __ 24  5
 
  8 __ 13 24  6  __  2 23 10 __  __ __ 22 __ __  19  1  7 25  9  21 18 11 __ __
  1 __ 22  2  5  11 18 __ __ __  __ 19 23 24 15  __ 17 21  3 __  __ 12  4 __  6
  3 __ __ 18 __  __ 12 __  8 13  __  5 __ __ __  22 23  6 14  4  15 __ 19 25 24
 14 19  4 __ 17  24 21 __ __ 22  11 25 18 12 10   2 __  8 __ __  16 20  7  3 __
 __ 15 21 __ __  __ __ 19  1 __  __ __  6 17 __  18 24 __ __ 16  13 __ 23 __ 22
 
 11 23 12 __ __  18 __ 17 __ __   6  1 10 19  3  15 16 14 21  2   4  7 __ __ __
  6  4 __ __  1  __  5 __  3 12  __ 24 25  8  2  __ 11 18 __ __  __ 19 21 17 __
 __  9 __ __ __  __ __ 13  6 10  22 __ 16 __  7  __  4 19  5 24  __ __ 12 __ __
 __ 20 19 __ __  __  7 14 11  8  __ 23 __ __ 21  17 25 __ __ __  __ 16 24 15 18
 24 17 __ __ __  21 __ 25 19 __   5 __ 20 __ __  __ __ 23 __ 12   6 __ __ __ __