250 excellent puzzle for Intermediate Players at the level of Medium. All riddles have only 1 solution. 2 puzzles per page.The font size is correct, you will not have to strain your eyes when solving puzzles.High quality paper and print (all puzzles read well,easy to write with pen and pencil without worry of bleed-through).Even-Odd Sudoku contains information about the evenness or oddness of the numbers in the cells. Cells with gray circles must contain odd numbers, cells with gray squares must contain even numbers.