with Ada.Text_IO;
with Ada.Integer_Text_IO;

procedure main is

   s, w : Integer;

begin

   Ada.Integer_Text_IO.Get(s, 0);
   Ada.Integer_Text_IO.Get(w, 0);
   
   if(s <= w)then
      Ada.Text_IO.Put_Line("unsafe");
   else
      Ada.Text_IO.Put_Line("safe");
   end if;

end main;
