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