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