Sudoku

Fill-in the missing numbers on the board, so that each row, each column and each 3x3 box has the numbers from 1 to 9 appearing only once.

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

Difficulty:

00:00