program p_006;{factorial}
var p,i,n,t:longint;
begin
  assign(input,'fact.in'); reset(input);
  assign(output,'fact.out'); rewrite(output);
  readln(p);
  if p=0 then write('1') else begin
    n:=5;
    while i<p do begin
      t:=n;
      while t mod 5=0 do begin
        t:=t div 5; i:=i+1; end;
      n:=n+5;
    end;
    write(n-5);
  end;
  close(input); close(output);
end.