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