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