Logic Masters Deutschland e.V.

The Rules:

1. [Sudoku]Normal sudoku rules apply - fill every row and column, and 3x3 region with digits from 1 to 9 once each.
2. [Crossword Shading] Shade some cells such that all shaded cells are 180° rotationally symmetric. (i.e. if R1C3 is shaded, R9C7 must be shaded).
   • All unshaded cells form 'words' which are 2-, 3-, 4-, 5-, 6-, 7-, 8-, or 9-digit numbers. (Note: no single digit words are allowed). "Words" that share a row or column must be separated by at least one shaded cell.
   • Each unshaded cell is part of a word both vertically and horizontally, and each word is assigned an across or down clue following standard crossword clueing rules
     (clues are labeled at the beginnings of each word).
   • All references to clues have been given
     (i.e, there is no valid 4-across clue).
   • Every word must contain at least one of the digits in its clues number somewhere in the answer. So 16A must contain a 1 and/or a 6 in it somewhere.
   • A few other clues have given below the grid.
     For example, 20A = 1A + 5A means that 20 across is equal to the sum of 1A and 5A.

An Example:

I've made a fully solvable 7x7 example if you'd like. Here's a picture of the puzzle, a picture progressing through the solve with the shaded cells, and the final solution.

If you'd like, feel free to read My Solution guide to the 7x7 puzzle. There is some similarity in the solve paths for both puzzles, so if you'd rather not spoiler things, maybe simply try it for yourself on Penpa or using Sven's Sudoku pad

The Puzzle:

Try it using Penpa. I recommend you use 1/4 mode for clue numbers, and L for cell contents.

Alternatively, you could solve it on

Sven's Sudoku pad If you use this, I recommend using the pen tool to highlight across and down answers that need specific digits, and erasing the pen lines as you know those words will contain the correct digits.