var f,g:text;
    p,n,j,a:longint;
    ok:boolean;
begin
assign(f,'fact.in');reset(f);
assign(g,'fact.out');rewrite(g);
read(f,p);ok:=true;
if p=0 then write(g,'1')
  else
  begin
  while ok do
    begin
    n:=n+5;a:=n;
    while a mod 5=0 do
      begin
      a:=a div 5;
      j:=j+1;
      end;
    if j=p then
      ok:=false;
    end;
  write(g,n);
  end;
close(g);
end.