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