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