Logic Masters Deutschland e.V.

Rules
Normal sudoku rules apply.
There are nine doubler cells in the grid, one in every row, column and box. Each digit from 1-9 appears in a doubler cell exactly once. A doubler cell's value counts as double its digit.
The value of each cell in the grid represents the height of a skyscraper. Clues outside the grid indicate the number of skyscrapers visible in that row or column, looking in that direction. Taller skyscrapers conceal smaller ones, and also those of the same height.

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