Logic Masters Deutschland e.V.

This puzzle is a tribute to the Swedish dish sandwich cake. It got this name because of how it has layers (well, some parts do) and it has sandwiches, so it's a perfect fit!

RULES:
- The grid consists of four overlapping sudoku grids of sizes 3x3, 4x4, 5x5 and 6x6, for which standard or irregular sudoku rules apply. (The regions in the 5x5 have been reinforced with cages to see them better.)
- Arrows are placed on all grid edges where the number outside the grid is a sandwich clue (the arrow points into the grid in question). Sandwich clues indicate the sum of the digits located between the lowest and highest digits in the row or column indicated, of that separate grid. All possible arrows are shown.
- White dots separate consecutive numbers. Black dots separate numbers with the ratio 1:2. These can be any numbers, if outside the grid.



Enjoy!

Links to solve it online:
Penpa+
SudokuPad