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);
  i:=0;
  if p=0 then write('1') else begin
    n:=5;
    while i<p do begin
      if n mod 25=0 then begin
        case n of
          25, 50, 75, 100, 150, 200, 300, 350, 400, 450: i:=i+2;
          125, 250, 500: i:=i+3;
          625: i:=i+4;
          3125: i:=i+5;
          else
           t:=n div 25; i:=i+2;
           while t mod 5=0 do begin t:=t div 5; i:=i+1; end;
        end;
        i:=i-1;
      end;
      n:=n+5; i:=i+1;
    end;
    if i=p then write(n-5) else write('-1');
  end;
  close(input); close(output);
end.