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