This year, we started posting some extra difficult Sunday Stumpers, about once a month. These will be quite tough puzzles, but with a logical path to be found (and solution videos to help). This eighth Sunday Stumper is a Hungarian Tapa from puzzlemaster Palmer Mebane.

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PDF

or solve online (using our beta test of Penpa-Edit tools)

Theme: Four Corners of Four

Author/Opus: This is the 52nd puzzle from our contributing puzzlemaster Palmer Mebane.

Rules: Variation of Tapa. Shade some empty cells black to create a single connected wall. Cells with numbers cannot be shaded, and the shaded cells cannot form a 2×2 square anywhere in the grid. Each row and column must contain eight shaded cells (four for the example). Place a number from 1 to 8 (1-4 for the example) into each shaded cell so that each number appears once in each row and column.

Numbers in a cell indicate the sums of the numbers of consecutive shaded blocks in the neighboring cells. If there is more than one number in a cell, then there must be at least one white (unshaded) cell between the black cell groups. Numbers on the shaded cells can repeat in a sum.

See also this example:

Difficulty: 5 stars

Time Standards (highlight to view): Grandmaster = 35:00, Master = 1:05:00, Expert = 2:10:00

Solution: PDF; a solution video is also available here.

Note: Follow this link for classic Tapa and this link for Tapa variations. If you are new to this puzzle type, here are our easiest Tapa puzzles to get started on. More Tapa puzzles can be found in The Art of Puzzles, in Tapa and Variations, and in our beginner-friendly collection Intro to GMPuzzles, all by Serkan Yürekli.