CF1027A.Palindromic Twist

You are given a string $s$ consisting of $n$ lowercase Latin letters. $n$ is even.

For each position $i$ ($1 \le i \le n$) in string $s$ you are required to change the letter on this position either to the previous letter in alphabetic order or to the next one (letters 'a' and 'z' have only one of these options). Letter in every position must be changed exactly once.

For example, letter 'p' should be changed either to 'o' or to 'q', letter 'a' should be changed to 'b' and letter 'z' should be changed to 'y'.

That way string "codeforces", for example, can be changed to "dpedepqbft" ('c' $\rightarrow$ 'd', 'o' $\rightarrow$ 'p', 'd' $\rightarrow$ 'e', 'e' $\rightarrow$ 'd', 'f' $\rightarrow$ 'e', 'o' $\rightarrow$ 'p', 'r' $\rightarrow$ 'q', 'c' $\rightarrow$ 'b', 'e' $\rightarrow$ 'f', 's' $\rightarrow$ 't').

String $s$ is called a palindrome if it reads the same from left to right and from right to left. For example, strings "abba" and "zz" are palindromes and strings "abca" and "zy" are not.

Your goal is to check if it's possible to make string $s$ a palindrome by applying the aforementioned changes to every position. Print "YES" if string $s$ can be transformed to a palindrome and "NO" otherwise.

Each testcase contains several strings, for each of them you are required to solve the problem separately.

给你一个由 $n$ 个小写拉丁字母组成的字符串 $s$，其中 $n$ 是偶数。

对于字符串 $s$ 中的每个位置 $i$（$1 \le i \le n$），你需要将该位置上的字母恰好更改一次，改为字母表中其前一个字母或后一个字母（字母 'a' 和 'z' 各只有一个相邻字母可选）。
例如：字母 'p' 可改为 'o' 或 'q'；字母 'a' 只能改为 'b'；字母 'z' 只能改为 'y'。

例如，字符串 "codeforces" 可以被更改为 "dpedepqbft"（'c' $\rightarrow$ 'd'，'o' $\rightarrow$ 'p'，'d' $\rightarrow$ 'e'，'e' $\rightarrow$ 'd'，'f' $\rightarrow$ 'e'，'o' $\rightarrow$ 'p'，'r' $\rightarrow$ 'q'，'c' $\rightarrow$ 'b'，'e' $\rightarrow$ 'f'，'s' $\rightarrow$ 't'）。

若一个字符串从左往右读与从右往左读完全相同，则称其为回文串。例如，"abba" 和 "zz" 是回文串，而 "abca" 和 "zy" 不是回文串。

你的目标是判断：能否通过对字符串 $s$ 的每个位置都执行上述更改操作，使其变为一个回文串？如果可以，输出 "YES"；否则，输出 "NO"。

每个测试用例包含多个字符串，对其中每一个字符串，你都需要独立求解该问题。

The first line contains a single integer $T$ ($1 \le T \le 50$) — the number of strings in a testcase.

Then $2T$ lines follow — lines $(2i - 1)$ and $2i$ of them describe the $i$-th string. The first line of the pair contains a single integer $n$ ($2 \le n \le 100$, $n$ is even) — the length of the corresponding string. The second line of the pair contains a string $s$, consisting of $n$ lowercase Latin letters.

第一行包含一个整数 $T$（$1 \le T \le 50$）—— 表示测试用例中字符串的个数。

接下来是 $2T$ 行——其中第 $(2i - 1)$ 行和第 $2i$ 行描述第 $i$ 个字符串。每对行中的第一行包含一个整数 $n$（$2 \le n \le 100$，且 $n$ 为偶数）—— 表示对应字符串的长度；该对行中的第二行包含一个字符串 $s$，由 $n$ 个小写拉丁字母组成。

Print $T$ lines. The $i$-th line should contain the answer to the $i$-th string of the input. Print "YES" if it's possible to make the $i$-th string a palindrome by applying the aforementioned changes to every position. Print "NO" otherwise.

输出 $T$ 行。第 $i$ 行应包含对输入中第 $i$ 个字符串的解答。如果可以通过对每个位置应用上述变换，使第 $i$ 个字符串变为回文串，则输出 "YES"；否则输出 "NO"。

The first string of the example can be changed to "bcbbcb", two leftmost letters and two rightmost letters got changed to the next letters, two middle letters got changed to the previous letters.

The second string can be changed to "be", "bg", "de", "dg", but none of these resulting strings are palindromes.

The third string can be changed to "beeb" which is a palindrome.

The fifth string can be changed to "lk", "lm", "nk", "nm", but none of these resulting strings are palindromes. Also note that no letter can remain the same, so you can't obtain strings "ll" or "mm".

示例中的第一个字符串可以变为 "bcbbcb"：最左侧的两个字母和最右侧的两个字母被更改为下一个字母，中间的两个字母被更改为前一个字母。

第二个字符串可以变为 "be"、"bg"、"de" 或 "dg"，但这些结果字符串均不是回文串。

第三个字符串可以变为 "beeb"，这是一个回文串。

第五个字符串可以变为 "lk"、"lm"、"nk" 或 "nm"，但这些结果字符串均不是回文串。另外请注意，任何字母都不能保持不变，因此无法得到字符串 "ll" 或 "mm"。