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