1  1  0  0 
 1 -1  0  0 
-1  1  0  0 
-1 -1  0  0 
 1  0  1  0 
 1  0 -1  0 
-1  0  1  0 
-1  0 -1  0 
 1  0  0  1 
 1  0  0 -1 
-1  0  0  1 
-1  0  0 -1 
 0  1  1  0 
 0  1 -1  0 
 0 -1  1  0 
 0 -1 -1  0 
 0  1  0  1 
 0  1  0 -1 
 0 -1  0  1 
 0 -1  0 -1 
 0  0  1  1 
 0  0  1 -1 
 0  0 -1  1 
 0  0 -1 -1 
a[ 1 ]:=[ 1,1,0,0];
a[ 2 ]:=[ 1,-1,0,0];
a[ 3 ]:=[ -1,1,0,0];
a[ 4 ]:=[ -1,-1,0,0];
a[ 5 ]:=[ 1,0,1,0];
a[ 6 ]:=[ 1,0,-1,0];
a[ 7 ]:=[ -1,0,1,0];
a[ 8 ]:=[ -1,0,-1,0];
a[ 9 ]:=[ 1,0,0,1];
a[ 10 ]:=[ 1,0,0,-1];
a[ 11 ]:=[ -1,0,0,1];
a[ 12 ]:=[ -1,0,0,-1];
a[ 13 ]:=[ 0,1,1,0];
a[ 14 ]:=[ 0,1,-1,0];
a[ 15 ]:=[ 0,-1,1,0];
a[ 16 ]:=[ 0,-1,-1,0];
a[ 17 ]:=[ 0,1,0,1];
a[ 18 ]:=[ 0,1,0,-1];
a[ 19 ]:=[ 0,-1,0,1];
a[ 20 ]:=[ 0,-1,0,-1];
a[ 21 ]:=[ 0,0,1,1];
a[ 22 ]:=[ 0,0,1,-1];
a[ 23 ]:=[ 0,0,-1,1];
a[ 24 ]:=[ 0,0,-1,-1];