Sudoku's simply solver

A simply sudoku's solver make with fotran language that show step by step the solution of the puzzle.
It is fast and light, not need installation - virus free.
1) open zip file into a directory
2) edit file text "matrice.txt" with notepad and insert the sudoku puzzle with zero on empty cell
3) start "solutore sudoku.exe"
4) insert on ms-dos window the sudoku dimension (es: 3 for 3x3 dimension)
5) push enter to see step by step the solution