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