\begin{problem}{Crystals}{crystals.in}{crystals.out}{2 sec}{256 Mb}

%Автор задачи:Артем Васильев 
%Автор условия:Малова Анна

Recent research in the laboratory of Anomalous Materials found a way to close the 
bridge between worlds. On Earth they discovered $n$ types of crystals. Study them, scientists 
have come to the conclusion that each of has a projection in a parallel dimension. 
Special detachment brought to the Earth the projections of all Earth crystals.

Further studies showed that each of the crystals found on both planets, characterized by a 
positive integer~--- \emph{the radiation power}. Crystals of $i$-th type have radiation power
$a_i$ and their projections have power $b_i$. To close the bridge, scientists should find a set 
of crystals that their total radiation power is be equal to the total power of their 
projections.

Help scientists to save the world.
                                                                  
\InputFile
The first line contains an integer $n$ ($1 \le n \le 10{\,}000$)~--- the number of the types of crystals.
Next line contains $n$ numbers $a_i$ ($0\le a_i \le {1\,}000$)~--- power of crystals found on Earth.
The last line contains $n$ numbers $b_i$ ($0\le b_i \le {1\,}000$)~--- power of their projections.

\OutputFile
If it is possible to close the bridge output in the first line the number $k$~--- the number of crystals required 
to close the bridge. In the second line output $k$ numbers, types of crystals that will be used in the experiment. 

If you can not close the bridge, print $-1$.

\Examples
\begin{example}%
\exmp{
3
3 4 5
1 6 2
}{
2
1 2
}%
\exmp{
3
3 6 5
1 4 2
}{
-1
}%
\end{example}

\Note
Solutuions that pass all tests where $n\le 100$, will get 60 points.

\end{problem}

