Normal sudoku rules apply. Digits along an arrow in the grid must sum to the digit in its circle. Digits may repeat along an arrow. Cells with a grey circle must be odd. Cells with a grey square must be even.
Normal sudoku rules apply. Digits along an arrow in the grid must sum to the digit in its circle. Digits may repeat along an arrow. Cells with a grey circle must be odd. Cells with a grey square must be even.