Kojun is a logic puzzle invented by Nikoli. A rectangular or square grid is divided into regions. Some cells contain numbers. Each region must be filled with each of the digits from 1 to the number of cells in the region. When two numbers are orthogonally adjacent, the numbers must be different. The upper number of two vertically adjacent numbers in the same region must be greater than the lower number. 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.