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