var f,g : text;
    t, p, i, l : longint;
 procedure pro(i:longint);
  begin
  while i mod 5 =0 do
  begin
   i:=i div 5;
   inc(t);
  end;
  end;
begin
 Assign(f,'fact.in');
  reset(f);
 Read(f,p);
 Close(f);
 i:=0;
  While t<p do
   begin
    inc(i,5);
    pro(i);
   end;





 Assign(g,'fact.out');
  Rewrite(g);

  if p=0 then
  Write(g,1)
   else
    if t>p then
      Write(g,-1)
      else
   Write(g
   ,i);
 Close(g);
end.