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