13. Place the addition and subtraction signs between the digits

$$
\begin{array}{lllllllll}
1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9
\end{array}
$$

so that the result is 100.
$\triangle$ For example, such an arrangement will work:

$$
123-4-5-6-7+8-9=100
$$

Answer: for example, $123-4-5-6-7+8-9=100$.