Normal sudoku rules apply. Digits on a red line must alternate between prime (2,3,5,7) and composite (4,6,8,9). The digit 1 is neither prime nor composite. The digits in each cage form a prime number when read rightwards or downwards. Digits in the circle must appear within the surrounding four cells. Digits in cells joined by a white dot must be consecutive and digits in cells joined by a black dot must be in a 2:1 ratio.