Logic Masters Deutschland e.V.

Greetings! Here's another Sudokuception puzzle I constructed. Enjoy!

Rules:

Normal sudoku rules apply. Each cell with a gray square must contain an even digit.

Numbers outside of the grid are normal little killer clues which give the sum of the digits along the marked diagonals. Digits may repeat along these diagonals. The variables x and y can be any positive or negative integers, and their values are to be determined.

There are four quadruples in the grid which form a valid 4x4 sudoku (if the space between the quadruples is ignored). Each quadruple clue must be surrounded by all of the digits from 1 to 4.

The red arrows in the grid are little killer clues for the 4x4 sudoku. For each of these arrows, the digit directly on top of the arrow must equal the sum of all quadruple cells in that direction. For example, r9c8 = r7c6 + r4c3. If an arrow points in multiple directions, then each direction must result in the same sum.

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