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