#include <bits/stdc++.h>
using namespace std;
int t, n;
char s[100000];
int main() {
  scanf("%d", &t);
  while (t--) {
    scanf("%d", &n);
    scanf("%s", s + 1);
    int l = 1, r = n, f = 0;
    while (l <= r) {
      if (l == r) break;
      int x = s[l] - 'a', y = s[r] - 'a';
      if (x == y || abs(x - y) == 2) {
        l++;
        r--;
      } else {
        f = 1;
        break;
      }
    }
    if (f == 1)
      printf("NO\n");
    else
      printf("YES\n");
  }
}
