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