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