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