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