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