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