Normal sudoku rules apply. Digits along an arrow must sum to the digit in that arrow's circle. A digit cannot repeat on a main diagonal (each marked in blue). The cell containing the opaque grey circle contains an odd digit.
Normal sudoku rules apply. Digits along an arrow must sum to the digit in that arrow's circle. A digit cannot repeat on a main diagonal (each marked in blue). The cell containing the opaque grey circle contains an odd digit.