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