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