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