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