(also known as " ") consists of a square grid divided into regions ("rooms"). Each room must be filled with each of the digits from 1 to the number of cells in the room. Every row and every column must contain the same amount of each digit. Same digits must not be orthogonally adjacent. The puzzle book contain: - 200 Puzzles - Handy 6 x 9 inch Book Layout - 2 Puzzles per Page - Ideal for Experts In the book you will find a description and examples of solutions for all puzzles. The book is for those who like logic and math problems. Decide, developing and improving.