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