
Hard and very hard training for the mind and energy for the brain. 200 KaKuro sudoku puzzle 16x16-17x17-19x19-20x20. 100 Su-Kro-Kuro sudoku puzzles 11x11 + 12x12. 100 Number Cross Sudoku - 25 puzzles 9x9, 25 puzzles 10x10 hard levels, 25 puzzles 11x11 and 25 puzzles 12x12 very...