Logic Masters Deutschland e.V.

Dutch Flat Mates: Confetti Sums

(Published on 7. January 2026, 07:00 by Flinty)

Previous Dutch Flat Mate Puzzles
This has been a weekly series since '18 Oct 23'. Here is a spreadsheet link for all the previous puzzles in the series, which also has a few teasers for upcoming constraints/guest setters in the series (subject to change).

This alternative link offers a limited LMD search for Dutch Flat Mates.

To play the puzzle, please click the image:


Puzzle Link: Click Here

Initial Setter Difficulty: 2-2.5 / 5

Normal Sudoku rules apply
Place the digits 1-9 so that they do not repeat in any row, column, or 3x3 box.

Dutch Flats
Every 5 in the grid must have a '1' directly above it or a '9' directly below it. It may have both, but it doesn't need both.

Confetti Sums
In ALL cases where the sum of two horizontally or vertically neighbouring digits is A or B; a circle is given. A and B stand for different numbers to be deduced
- White is always A
- Black is always B
- Grey is ambigous, and is either A or B.

Hint to start

A and B are heavily restricted by maths/options in Boxes 2 and 8, with Flat Mates in C5 being the key. The negative constraint is hugely powerful throughout the solve.

Guest Setter
Another series debutant next week, another "A-Tier Setter" series debutant at that! Qodec with Between Lines!

Busy Week For Flat Mates
The wonderful puzzle pack Zodiac x Flat Mates from ViKingPrime had a small issue with Puzzle 6. This has been resolved and I do hope you give it another try!

We also had bonus Flat Mates from aqjhs in the form of a CTC Discord Secret Santa gift for me which is great and well worth checking out: Dutch Flat Mates: Dual Duel. As well as the Scojo Discord Prompt "Wheel" spinning Squisdoku and Flat Mates, so puzzles with those combinations should be making an appearance on LMD.

Solution code: Row 1 Digits

Last changed on yesterday, 13:25

Solved by Dermerlin, OJPS, luoji, tuturitu, palpot, damo_89, da-hans, jalebc, Aaravos, goodcity, Gribba Bibba, zrbakhtiar, Bjd, hollowpineapple, biorycbyd, marcmees, olliwright, Franjo, teuthida, meiwanmeiliao, achim-t, Malakree, Byon, Exigus, Ikke Moon, Qodec, sorryimLate, SKORP17, Ragna, Elliott810, SanFranSam, aqjhs, nyxie, Digbog26, NEWS, KirkFox, walid_tun, harwiltz, gdc
Full list

Comments

yesterday, 13:25 by Flinty
Capitilsed the word "ALL" in the rules to emphasise the negative constraint.

yesterday, 05:13 by aqjhs
excellent use of the negative constraint

Last changed yesterday, 02:08

yesterday, 02:08 by SanFranSam
I did solve it without the hint but I think the negative constraint could have been stated more clearly. Wouldn't have solved it but for damo_89's note.

on 7. January 2026, 16:06 by Franjo
Thank you very much for creating and sharing another lovely DFM-puzzle.

Last changed on 7. January 2026, 12:01

on 7. January 2026, 08:59 by damo_89
Don't forget the negative constraint!

Flinty: Don't be a dozy sausage! x

Difficulty:2
Rating:90 %
Solved:39 times
Observed:0 times
ID:000QV3

Puzzle variant

Enter solution

Solution code:

Login