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