function s = symdyn(orbit)

cnt = 0;
[d,n] = size(orbit);
s = [];
for i = 1:n-1
  if((orbit(3,i) <= 27) & (orbit(3,i+1)> 27))
      cnt = cnt+1;
      if(orbit(2,i) < 0)
        s = [s,'A'];
      else
        s = [s,'B'];
       end
    end
end
if((orbit(3,n) <= 27) & (orbit(3,1)> 27))
   cnt = cnt+1;
   if(orbit(2,n) < 0)
     s = [s,'A'];
   else
     s = [s,'B'];
   end
end