(also known as " ") is a logic puzzle that has simple rules, but which provides sufficient challenges to satisfy the most enthusiastic solvers!The task consists of a rectangular or square grid divided into regions.Each region must be filled with each of the digits from 1 to the number of cells in the region.Cells with the same digits must not be orthogonally or diagonally adjacent.Even though the rules are simple, you will need all your skills to solve it. 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.