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