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