2026-09-21 daily answer

Step-by-step reasoning

1. Region 1 has only one safe cell left: R1C7.
2. R1C7 rules out cells in its row, column, color region, and touching neighborhood.
3. Region 4 has only one safe cell left: R4C3.
4. R4C3 rules out cells in its row, column, color region, and touching neighborhood.
5. Region 6 has only one safe cell left: R6C4.
6. R6C4 rules out cells in its row, column, color region, and touching neighborhood.
7. Region 7 has only one safe cell left: R7C6.
8. R7C6 rules out cells in its row, column, color region, and touching neighborhood.
9. Row 5 has only one safe cell left: R5C1.
10. R5C1 rules out cells in its row, column, color region, and touching neighborhood.
11. Row 3 has only one safe cell left: R3C5.
12. R3C5 rules out cells in its row, column, color region, and touching neighborhood.
13. Row 2 has only one safe cell left: R2C2.