Filomino

[from nikoli website]

1. Fill in all empty cells with numbers under the following rules:
2. The area, connected by the same numbers horizontally or vertically, is called "Block". Separate the entire board by Blocks.
3. Each Block contains as many cells as the number it contains (e.g., a Block of 6 has 6 cells).
4. Blocks of the same size must not touch each other, horizontally or vertically.

Solution: