var v:array[1..2000001]of shortint;
    p:array[1..1000000]of longint;
    n,j,k,u:int64;
    i:longint;
    f:text;
begin
   assign(f,'ciur.in');
   reset(f);
   read(f,n);
   close(f);
   for i:=2 to n do
   if v[i]=0 then begin u:=u+1;
                        p[u]:=i;
                        j:=i;
                        while j<n do
                        begin
                        j:=j+i;
                        v[j]:=1;
                        end;
                  end;
   assign(f,'ciur.out');
   rewrite(f);
   writeln(f,u);
   for i:=1 to u do
   write(f,p[i],' ');
   writeln(f);
   close(f);
end.