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