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