X ( 2 , 11 , 3 , 12 ) X ( 4 , 17 , 5 , 18 ) X ( 6 , 2 , 7 , 1 ) X ( 8 , 19 , 9 , 20 ) X ( 10 , 3 , 11 , 4 ) X ( 12 , 8 , 13 , 7 ) X ( 13 , 22 , 14 , 1 ) X ( 15 , 20 , 16 , 21 ) X ( 16 , 5 , 17 , 6 ) X ( 18 , 9 , 19 , 10 ) X ( 21 , 14 , 22 , 15 ) {\displaystyle X(2,11,3,12)X(4,17,5,18)X(6,2,7,1)X(8,19,9,20)X(10,3,11,4)X(12,8,13,7)X(13,22,14,1)X(15,20,16,21)X(16,5,17,6)X(18,9,19,10)X(21,14,22,15)}