SUDOKU

Write a number from 1 to 9 into each empty square in the grid so that every number from 1 to 9 appears exactly once in each horizontal row, each vertical column, and each 3×3 block.
9    5    6    
  6    3    1  
    7    1    9
2    9    4    
  9    4    6  
    6          2
3    4    9    
  1    6        
    2    7    8
* Easy