Logic Masters Deutschland e.V.

Normal sudoku rules apply. The killer cages acts as regions and cells must be shaded following regular stostone rules. (Regular stostone rules explained under the puzzle.) Every column must have exactly 5 shaded cells. Digits in the shaded cells of a cage sum to the number in the corner of a cage. Digits can't repeat in a cage.

You can solve this in f-puzzles.

Stostone rules from www.janko.at:
1. Blacken some cells of the grid [paper] resp. color the gray cells of the grid black or white [interactively].
2. A number in a region indicates how many cells in this region must be blackened. In regions without a number an arbitrary number of cells (at least one) may be blackened.
3. Within a region the black cells must form a stone, an orthogonally contiguous area.
4. Black cells must not be orthogonally adjacent across borders.
5. If all stones »fall down«, they must cover the lower half of the grid completely without gaps.

Example