Watch the complete walkthrough
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Look before you double-tap
Follow this easy 5×5 board one deduction at a time. Count rows downward and columns rightward, starting at 1.
Tap once to mark × and double-tap to place a koala. Five rows, columns and regions require five koalas.
Figure 1: look for single-square regions.
1. Row 1, column 3 is certain
It forms a region by itself. Double-tap it, then mark the rest of row 1, column 3, and its neighbors.
Figure 2: marks record deductions, not trial placements.
2. Place row 2, column 1
This is another single-square region. It shares neither row nor column with the first koala, and their columns differ by 2, so they do not touch. Place it and exclude its row, column and neighbors.
3. The large region has only row 3, column 5
Its squares in rows 1 and 2 are excluded. Columns 1 and 3 are occupied. Row 3 column 2 also touches the second koala diagonally. The large region has just one candidate left: row 3, column 5.
Figure 3: exclusions turn a large region into a single candidate.
4. Row 4 has only column 2
Columns 1, 3 and 5 are occupied. Row 4 column 4 touches the third koala diagonally. That leaves column 2. Double-tap it.
5. Finish at row 5, column 4
These are the only unused row and column. Check that the intersection belongs to the last unused region and touches no koala, then place it.
The final columns, from row 1 through row 5, are 3, 1, 5, 2, 4. Each column and region appears once. Consecutive rows have column differences greater than 1, so there is no diagonal contact.
What to take into your next puzzle
Single-square regions give certain starting points. Exclude systematically after every placement, then recheck larger regions. If you need control practice, use the playable tutorial. Next, learn 7×7 candidate pairs.