Variations: Magic squares constructed from mutually orthogonal doubly diagonal Graeco-Latin squares are interesting in themselves since the magic property emerges from the relative position of the alphabets in the square, and not due to any arithmetic property of the value assigned to them. This means that we can assign any value to the alphabets of such squares and still obtain a magic square. This is the basis for constructing squares that display some information (e.g. birthdays, years, etc.) in the square and for creating "reversible squares". For example, we can display the number "π" ≈ at the bottom row of a 4×4 magic square using the Graeco-Latin square given above by assigning ("α", "β", "γ", "δ") = (10, 0, 90, 15) and ("a", "b", "c", "d") = (0, 2, 3, 4). We will obtain the following non-normal magic square with the magic sum 124: