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