250 excellent puzzles. Levels go on increasing. You can start with a bronze medalist, this is the first 80 puzzles 10 x 10. You can go to the champion, the gold prize - 90 extreme Sudoku 20 x 20. Silver puzzles 15 x 15 are in the middle of the book. All riddles have only 1 solution. 2 puzzles per page. Enough space for your thoughts and decisions. Very convenient and practical. Good brain support in shape. Expands creative thinking. Wide internal edges allow you to record solutions. Ideal gift for all fans of puzzles.A logical puzzle. It is a rectangular grid, in some cells of which there are numbers. It is required to fill empty cells in such a way that all numbers are connected in series, horizontally or vertically. Moving diagonally is not allowed.A great book for relaxing in your spare time. Presented 150 pages. The format is 8.5 '' x 11 ''. I hope you enjoy my book. Sudoku will provide you with relaxation, color your leisure, turn your free time into relaxation, give a vacation from the day for your mind, add zest, develop memory, develop logical thinking and concentration of attention.I would also be very grateful if you could write a review.Thank you.Best regards,Andrii Pitenko