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