Life Sudoku

Every day a new Life Sudoku, there is also an archive of one month. Click on a box and then on one of the digits that appear. To fill in a pencil mark, the option pencil marks must be on and then click on the small square in the corner of each box. Use the Sudoku rules to solve the puzzle: in every row, column and 3x3 box the numbers 1-9 can only appear once.