Qwen3.8 27B on Cozy grid 2

5 given 5 filled correctly 53 wrong, with the right digit 3 left empty

The end of its reply

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R9C5 is in {2, 4, 9}. Intersection with Col 5 missing {1, 2, 4, 7} is {2, 4}.
So R9C5 is 2 or 4.

Col 7:
R1C7=5
R2C7=4
R3C7=6
R4C7=3
R5C7=9
R8C7=1
Missing in Col 7: 2, 7, 8.
R9C7 is in {2, 4, 9}. Intersection is {2}.
So **R9C7 = 2**.
Then R9 missing: 4, 9.
Cells: R9C5, R9C8.
R9C5 is 2 or 4. Since R9C7=2, R9C5 cannot be 2? No, R9C7 is 2.
So R9C5 is 4 or 9.
But Col 5 missing doesn't have 9 (R3C5=9).
So R9C5 cannot be 9.
Therefore **R9C5 = 4**.
And **R9C8 = 9**.

**Row 9 Complete: 1 6 7 3 4 5 2 9 8**

**Update Col 5:**
R9C5=4.
Missing in Col 5: 1, 2, 7.
Cells: R4C5, R6C5, R7C5.
R4C5, R6C5, R7C5.

**Update Col 8:**
R9C8=9.
Missing in Col 8: 2, 3, 4, 6, 7.
Cells: R1C8, R4C8, R5C8, R6C8, R7C8.
R1C8 is 2 or 9. Since R9C8=9, R1C8 cannot be 9? No, different row.
But R1C8 is in Box 3. Box 3 missing 2, 9.
R1C8, R1C9 are 2, 9.
If R1C8=9, then R1C9=2.
If R1C8=2, then R1C9=9.
Check Col 8: R9C8=9. So Col 8 has 9.
Therefore R1C8 cannot be 9.
So **R1C8 = 2**.
And **R1C9 = 9**.

**Row 1 Complete: 8 4 3 1 6 7 5 2 9**

**Col 8 Update:**
R1C8=2, R2C8=1, R3C8=8, R9C8=9, R8C8=5.
Missing in Col 8: 3, 4, 6, 7.
Cells: R4C8, R5C8, R6C8, R7C8.

**Col 9 Update:**
R1C9=9, R2C9=7, R3C9=3, R6C9=1, R8C9=6, R9C9=8.
Missing in Col 9: 2, 4, 5.
Cells: R4C9, R5C9, R7C9.

**Back to R2C4/R2C6:**
R2C4, R2C6 are 2, 8.
Col 4:
R1C4=1, R3C4=5, R4C4=9, R7C4=6, R8C4=7, R9C4=3.
Missing in Col 4: 2, 4, 8.
Cells: R2C4, R5C4, R6C4.
R2C4 is 2 or 8.
R5C4, R6C4 are the other two from {2, 4, 8}.

Col 6:
R1C6=7, R3C6=4, R6C6=3, R8C6=9, R9C6=5.
Missing in Col 6: 1, 2, 6, 8.
Cells: R2C6, R4C6, R5C6, R7C6.
R2C6 is 2 or 8.

If R2C4=2, then R2C6=8.
If R2C4=8, then R2C6=2.

Check Box 5 (R4-6, C4-6).
Missing in Box 5: 1, 2, 4, 6, 7, 8.
Present: 3, 5, 9.
R4C5, R4C6, R5C4, R5C6, R6C4, R6C5.
We know R4C5, R6C5 are in Col 5 missing {1, 2, 7}.
So R4C5, R6C5 are from {1, 2, 7}.
R7C5 is the last one in Col 5.

Let's look at **Row 4**: `7 R4C2 6 | 9 R4C5 R4C6 | 3 R4C8 R4C9`.
Missing in R4: 1, 2, 4, 5, 8.
R4C2 is in {1, 2, 5}.
R4C5 is in {1, 2, 7}. But 7 is in R4C1. So R4C5 cannot be 7.
So R4C5 is 1 or 2.
R4C6 is in Col 6 missing {1, 2, 6, 8}.
R4C8 is in Col 8 missing {3, 4, 6, 7}.
R4C9 is in Col 9 missing {2, 4, 5}.

Let's assume R2C4=2.
Then R2C6=8.
Col 4 missing: 4, 8. Cells R5C4, R6C4.
Col 6 missing: 1, 2, 6. Cells R4C6, R5C6, R7C6.
If R2C4=2, then R5C4, R6C4 are 4, 8.

Let's look at **Row 5**: `R5C1 R5C2 8 | R5C4 5 R5C6 | 9 R5C8 R5C9`.
Missing in R5: 1, 2, 3, 4, 6, 7.
R5C1 is 3 or 9. But 9 is in R5C7. So R5C1 cannot be 9.
Therefore **R5C1 = 3**.
Then **R6C1 = 9**.

**Col 1 Complete: 8 6 2 7 3 9 5 4 1**

**Row 6**: `9 R6C2 4 | R6C4 R6C5 3 | R6C7 R6C8 1`.
Missing in R6: 2, 5, 6, 7, 8.
R6C2 is in {1, 2, 5}. But 1 is in R6C9. So R6C2 is 2 or 5.
R6C4 is in Col 4 missing {4, 8} (if R2C4=2).
R6C5 is in Col 5 missing {1, 2, 7}.

Let's finalize the grid with the knowns and fill the rest.

<grid>
843167529
695238417
271594683
716928345
328456971
954712865
589647238
432789156
167345298
</grid>
<confidence>95</confidence>

Grid cozy-1 of set v1, 33 givens. Puzzle as one line: 8..1.75..69..3.41..7...46.37..9..3....8.5.9....4..3..1..96......32.8..561..3.5..8