Description:
Polycarp has a string $$$s$$$, which consists of lowercase Latin letters. He encodes this string using the following algorithm:
- first, he constructs a new auxiliary string $$$r$$$, which consists of all distinct letters of the string $$$s$$$, written in alphabetical order;
- then the encoding happens as follows: each character in the string $$$s$$$ is replaced by its symmetric character from the string $$$r$$$ (the first character of the string $$$r$$$ will be replaced by the last, the second by the second from the end, and so on).
For example, encoding the string $$$s$$$="codeforces" happens as follows:
- the string $$$r$$$ is obtained as "cdefors";
- the first character $$$s_1$$$='c' is replaced by 's';
- the second character $$$s_2$$$='o' is replaced by 'e';
- the third character $$$s_3$$$='d' is replaced by 'r';
- ...
- the last character $$$s_{10}$$$='s' is replaced by 'c'.
The string $$$r$$$ and replacements for $$$s$$$="codeforces".
Thus, the result of encoding the string $$$s$$$="codeforces" is the string "serofedsoc".
Write a program that performs decoding — that is, restores the original string $$$s$$$ from the encoding result.
Input Format:
The first line contains a single integer $$$t$$$ ($$$1 \le t \le 10^4$$$) — the number of test cases.
The first line of each test case contains a single integer $$$n$$$ ($$$1 \le n \le 2 \cdot 10^5$$$) — the length of the string $$$b$$$.
The second line of each test case contains a string $$$b$$$ of length $$$n$$$, consisting of lowercase Latin letters — the result of encoding the original string $$$s$$$.
It is guaranteed that the sum of the values of $$$n$$$ over all test cases in the test does not exceed $$$2 \cdot 10^5$$$.
Output Format:
For each test case, output the string $$$s$$$ from which the encoding result $$$b$$$ was obtained.
Note:
None