Normal sudoku rules apply. In cages, digits must sum to the small clue in the top left corner of the cage. Digits cannot repeat within a cage. The grey lines are palindromes (ie they must read the same in both directions). The indicated diagonal sums to 45 - digits may repeat along this diagonal. Cells a "camel move" apart may not contain the same digit. A camel move is like an elongated knight in chess - it makes a {1,3} jump.