X ( 1 , 13 , 2 , 12 ) X ( 3 , 15 , 4 , 14 ) X ( 5 , 17 , 6 , 16 ) X ( 7 , 19 , 8 , 18 ) X ( 9 , 21 , 10 , 20 ) X ( 11 , 1 , 12 , 22 ) X ( 13 , 3 , 14 , 2 ) X ( 15 , 5 , 16 , 4 ) X ( 17 , 7 , 18 , 6 ) X ( 19 , 9 , 20 , 8 ) X ( 21 , 11 , 22 , 10 ) {\displaystyle X(1,13,2,12)X(3,15,4,14)X(5,17,6,16)X(7,19,8,18)X(9,21,10,20)X(11,1,12,22)X(13,3,14,2)X(15,5,16,4)X(17,7,18,6)X(19,9,20,8)X(21,11,22,10)}