Diagonal sandwich sudoku

Diagonal Sandwich Sudoku is a variation of Sudoku that adds two additional rules to the standard rules of Sudoku:

• The numbers 1 to 9 must also appear in the two diagonals of the puzzle, without repetitions.

• The highest and lowest digit on these diagonals may not repeat but all other digits may, as long as it does not break other rules.

This means that there are now a total of 108 cells in the puzzle, and each number from 1 to 9 must appear exactly once in each row, column, diagonal, and 3x3 block.