Even-Odd Sudoku - 200 Easy Puzzles 9x9 (Volume 2)

Sudoku (also known as "Number Place") is a placement puzzle.

The puzzle is most frequently a 9 x 9 grid made up of 3 x 3 subgrids (called "regions").

Some cells already contain numbers, known as "givens".

The goal is to fill in the empty cells, one number in each, so that each column, row, and region contains the numbers 1 through 9 exactly once.

Each number in the solution therefore occurs only once in each of three "directions", hence the "single numbers" implied by the puzzle's name. Even-Odd Sudoku: fill in the grid so that every row, every column, and every 3 x 3 box contains the digits 1 through 9. Cells with gray circles must contain odd digits, cells with gray squares must contain even digits.