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