If a 3x3 Latin square has row 1 = [A, B, C] and row 2 = [C, A, B], what is row 3?
For col 1: A and C are used, so row 3 col 1 is B. For col 2: B and A are used, so row 3 col 2 is C. For col 3: C and B are used, so row 3 col 3 is A.