#include <bits/stdc++.h>
int main(void) {
  int n, i, j, tmp, mark = 0;
  char *s;
  scanf("%d", &n);
  while (n) {
    n--;
    scanf("%d", &i);
    s = new char[i + 1];
    scanf("%s", s);
    for (j = 0; j <= i - 1; j++) {
      tmp = s[j] - s[i - 1 - j];
      if (tmp != 2 && tmp != -2 && tmp != 0) {
        printf("NO\n");
        mark = 1;
        break;
      }
    }
    if (mark == 1) {
      mark = 0;
      delete[] s;
      continue;
    }
    printf("YES\n");
    delete[] s;
  }
  return 0;
}
