var v:array [1..2000000] of integer;
    n,i,j,k:longint;
begin
 assign(input,'ciur.in'); reset(input);
 assign(output,'ciur.out'); rewrite(output);
  readln(n);
  for i:=2 to n do
   if v[i]=0 then begin
    inc(k);
    for j:=2  to n div i do v[i*j]:=1;
   end;
  writeln(k); j:=0;
  for i:=n downto 1 do begin
   inc(j);
   if v[i]=0 then write(i,' ');
   if j=1000 then break;
  end;
 close(input); close(output);
end.