- 250 wonderful puzzles + surprise in 250 classic sudoku very hard (need to download and print).- Sudoku 9x9, separated by smaller squares of 3x3 cells. The entire playing field consists of 81 cells. It is required to fill empty cells with numbers from 1 to 9, each of the digits should appear only once in each row, column, and 3x3 square. The sum of all the numbers in the cage must correspond to the number printed in the corner.- levels continue to please. 50 Easy + 50 Medium + 50 Hard + 100 Very hard- all riddles have only one verified solution- 2 puzzles on 1 page, very practical and convenient- a lot of free space for the progress of your thoughts- good mind support in the excellent form- large font- develops memory, logical thinking, helps to focus- creative possibilities are expandingIdeal gift for all fans of puzzles. An excellent book for free time and learning of the mind. I hope you enjoy the book. I would be very grateful if you write a review.Best regards,Andrii Pitenko