var n,k,c:longint;
    f,g:text;
    v:array[1..10] of longint=(1,5,25,125,625,3125,15625,78125,390625,1953125);
begin
  assign(f,'ciur.in');
  assign(g,'ciur.out');
  reset(f);
  rewrite(g);
  readln(f,n);
  c:=0;
  k:=0;
  while n>0 do
    begin
      inc(c);
      k:=k+((n mod 10+1) div 2)*v[c];
      n:=n div 10;
    end;
  writeln(g,k);
  close(f);
  close(g);
end.