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