Add Plus Minus Sign

Description:

Input:

The first line contains a single integer $$$t$$$ ($$$1 \leq t \leq 2\,000$$$)  – the number of test cases. The description of test cases follows.

The first line of each test case contains a single integer $$$n$$$ ($$$2 \leq n \leq 100$$$) — the length of $$$a$$$.

The second line of each test case contains a string $$$a$$$ of length $$$n$$$, consisting of only $$$0$$$ and $$$1$$$.

Output:

For each test case, output a string of length $$$n - 1$$$ consisting of $$$-$$$ and $$$+$$$ on a separate line. If there is more than one assignment of signs that produces the smallest possible absolute value, any of them is accepted.

Sample Input:

3
2
11
5
01101
5
10001

Sample Output:

-
+-++
+++-

Note:

In the first test case, we can get the expression $$$1 - 1 = 0$$$, with absolute value $$$0$$$.

In the second test case, we can get the expression $$$0 + 1 - 1 + 0 + 1 = 1$$$, with absolute value $$$1$$$.

In the third test case, we can get the expression $$$1 + 0 + 0 + 0 - 1 = 0$$$, with absolute value $$$0$$$.